diff --git a/app/assets/stylesheets/framework.scss b/app/assets/stylesheets/framework.scss
index 35e7a10379f488be328653f25cfe27dae2211f2b..c0524bf6aa3d84787ad075b228d03caf8346d2a8 100644
--- a/app/assets/stylesheets/framework.scss
+++ b/app/assets/stylesheets/framework.scss
@@ -19,7 +19,6 @@
 @import "framework/flash";
 @import "framework/forms";
 @import "framework/gfm";
-@import "framework/gitlab-theme";
 @import "framework/header";
 @import "framework/highlight";
 @import "framework/issue_box";
diff --git a/app/assets/stylesheets/framework/gitlab-theme.scss b/app/assets/stylesheets/framework/gitlab-theme.scss
deleted file mode 100644
index 71f764923ffa5134b07cdbb0d551cf25a07568b5..0000000000000000000000000000000000000000
--- a/app/assets/stylesheets/framework/gitlab-theme.scss
+++ /dev/null
@@ -1,265 +0,0 @@
-/**
- * Styles the GitLab application with a specific color theme
- */
-
-@mixin gitlab-theme($color-100, $color-200, $color-500, $color-700, $color-800, $color-900, $color-alternate) {
-  // Header
-
-  header.navbar-gitlab-new {
-    background: linear-gradient(to right, $color-900, $color-800);
-
-    .navbar-collapse {
-      color: $color-200;
-    }
-
-    .container-fluid {
-      .navbar-toggle {
-        border-left: 1px solid lighten($color-700, 10%);
-      }
-    }
-
-    .navbar-sub-nav,
-    .navbar-nav {
-      > li {
-        > a:hover,
-        > a:focus {
-          background-color: rgba($color-200, .2);
-        }
-
-        &.active > a,
-        &.dropdown.open > a {
-          color: $color-900;
-          background-color: $color-alternate;
-
-          svg {
-            fill: currentColor;
-          }
-        }
-
-        &.line-separator {
-          border-left: 1px solid rgba($color-200, .2);
-        }
-      }
-    }
-
-    .navbar-sub-nav {
-      color: $color-200;
-    }
-
-    .nav {
-      > li {
-        color: $color-200;
-
-        > a {
-          svg {
-            fill: $color-200;
-          }
-
-          &.header-user-dropdown-toggle {
-            .header-user-avatar {
-              border-color: $color-200;
-            }
-          }
-
-          &:hover,
-          &:focus {
-            @media (min-width: $screen-sm-min) {
-              background-color: rgba($color-200, .2);
-            }
-
-            svg {
-              fill: currentColor;
-            }
-          }
-        }
-
-        &.active > a,
-        &.dropdown.open > a {
-          color: $color-900;
-          background-color: $color-alternate;
-
-          &:hover {
-            svg {
-              fill: $color-900;
-            }
-          }
-        }
-
-        .impersonated-user,
-        .impersonated-user:hover {
-          svg {
-            fill: $color-900;
-          }
-        }
-      }
-    }
-  }
-
-  .title {
-    > a {
-      &:hover,
-      &:focus {
-        background-color: rgba($color-200, .2);
-      }
-    }
-  }
-
-  .search {
-    form {
-      background-color: rgba($color-200, .2);
-
-      &:hover {
-        background-color: rgba($color-200, .3);
-      }
-    }
-
-    .location-badge {
-      color: $color-100;
-      background-color: rgba($color-200, .1);
-      border-right: 1px solid $color-800;
-    }
-
-    .search-input::placeholder {
-      color: rgba($color-200, .8);
-    }
-
-    .search-input-wrap {
-      .search-icon,
-      .clear-icon {
-        color: rgba($color-200, .8);
-      }
-    }
-
-    &.search-active {
-      form {
-        background-color: $white-light;
-      }
-
-      .location-badge {
-        color: $gl-text-color;
-      }
-
-      .search-input-wrap {
-        .search-icon {
-          color: rgba($color-200, .8);
-        }
-      }
-    }
-  }
-
-  .btn-sign-in {
-    background-color: $color-100;
-    color: $color-900;
-  }
-
-
-  // Sidebar
-  .nav-sidebar li.active {
-    box-shadow: inset 4px 0 0 $color-700;
-
-    > a {
-      color: $color-900;
-    }
-
-    svg {
-      fill: $color-900;
-    }
-  }
-}
-
-
-body {
-  &.ui_indigo {
-    @include gitlab-theme($indigo-100, $indigo-200, $indigo-500, $indigo-700, $indigo-800, $indigo-900, $white-light);
-  }
-
-  &.ui_dark {
-    @include gitlab-theme($theme-gray-100, $theme-gray-200, $theme-gray-500, $theme-gray-700, $theme-gray-800, $theme-gray-900, $white-light);
-  }
-
-  &.ui_blue {
-    @include gitlab-theme($theme-blue-100, $theme-blue-200, $theme-blue-500, $theme-blue-700, $theme-blue-800, $theme-blue-900, $white-light);
-  }
-
-  &.ui_green {
-    @include gitlab-theme($theme-green-100, $theme-green-200, $theme-green-500, $theme-green-700, $theme-green-800, $theme-green-900, $white-light);
-  }
-
-  &.ui_light {
-    @include gitlab-theme($theme-gray-900, $theme-gray-700, $theme-gray-800, $theme-gray-700, $theme-gray-700, $theme-gray-100, $theme-gray-700);
-
-    header.navbar-gitlab-new {
-      background: $theme-gray-100;
-      box-shadow: 0 2px 0 0 $border-color;
-
-      .logo-text svg {
-        fill: $theme-gray-900;
-      }
-
-      .navbar-sub-nav,
-      .navbar-nav {
-        > li {
-          > a:hover,
-          > a:focus {
-            color: $theme-gray-900;
-          }
-
-          &.active > a {
-            color: $white-light;
-
-            &:hover {
-              color: $white-light;
-            }
-          }
-        }
-      }
-
-      .container-fluid {
-        .navbar-toggle,
-        .navbar-toggle:hover {
-          color: $theme-gray-700;
-          border-left: 1px solid $theme-gray-200;
-        }
-      }
-    }
-
-    .search {
-      form {
-        background-color: $white-light;
-        box-shadow: inset 0 0 0 1px $border-color;
-
-        &:hover {
-          background-color: $white-light;
-          box-shadow: inset 0 0 0 1px $blue-100;
-
-          .location-badge {
-            box-shadow: inset 0 0 0 1px $blue-100;
-          }
-        }
-      }
-
-      .search-input-wrap {
-        .search-icon {
-          color: $theme-gray-200;
-        }
-      }
-
-      .location-badge {
-        color: $theme-gray-700;
-        box-shadow: inset 0 0 0 1px $border-color;
-        background-color: $nav-badge-bg;
-        border-right: 0;
-      }
-    }
-
-    .nav-sidebar li.active {
-      > a {
-        color: $theme-gray-900;
-      }
-
-      svg {
-        fill: $theme-gray-900;
-      }
-    }
-  }
-}
diff --git a/app/assets/stylesheets/framework/header.scss b/app/assets/stylesheets/framework/header.scss
index ab3c34df1fb75030ba10fdd7e68c4ffae8449d3a..b00a2d053e2cf8d818946a33c781c3f6ae032e28 100644
--- a/app/assets/stylesheets/framework/header.scss
+++ b/app/assets/stylesheets/framework/header.scss
@@ -111,6 +111,7 @@ header {
         svg {
           height: 16px;
           width: 23px;
+          fill: currentColor;
         }
       }
 
diff --git a/app/assets/stylesheets/framework/variables.scss b/app/assets/stylesheets/framework/variables.scss
index 3857226cddb543d5ad76c511f457d271f3a9400a..e300b006026eeccad15508c01f22bc42c0d3f436 100644
--- a/app/assets/stylesheets/framework/variables.scss
+++ b/app/assets/stylesheets/framework/variables.scss
@@ -74,8 +74,6 @@ $red-700: #a62d19;
 $red-800: #8b2615;
 $red-900: #711e11;
 
-// GitLab themes
-
 $indigo-50: #f7f7ff;
 $indigo-100: #ebebfa;
 $indigo-200: #d1d1f0;
@@ -88,43 +86,6 @@ $indigo-800: #393982;
 $indigo-900: #292961;
 $indigo-950: #1a1a40;
 
-$theme-gray-50: #fafafa;
-$theme-gray-100: #f2f2f2;
-$theme-gray-200: #dfdfdf;
-$theme-gray-300: #cccccc;
-$theme-gray-400: #bababa;
-$theme-gray-500: #a7a7a7;
-$theme-gray-600: #949494;
-$theme-gray-700: #707070;
-$theme-gray-800: #4f4f4f;
-$theme-gray-900: #2e2e2e;
-$theme-gray-950: #1f1f1f;
-
-$theme-blue-50: #f4f8fc;
-$theme-blue-100: #e6edf5;
-$theme-blue-200: #c8d7e6;
-$theme-blue-300: #97b3cf;
-$theme-blue-400: #648cb4;
-$theme-blue-500: #4a79a8;
-$theme-blue-600: #3e6fa0;
-$theme-blue-700: #305c88;
-$theme-blue-800: #25496e;
-$theme-blue-900: #1a3652;
-$theme-blue-950: #0f2235;
-
-$theme-green-50: #f2faf6;
-$theme-green-100: #e4f3ea;
-$theme-green-200: #c0dfcd;
-$theme-green-300: #8ac2a1;
-$theme-green-400: #52a274;
-$theme-green-500: #35935c;
-$theme-green-600: #288a50;
-$theme-green-700: #1c7441;
-$theme-green-800: #145d33;
-$theme-green-900: #0d4524;
-$theme-green-950: #072d16;
-
-
 $black: #000;
 $black-transparent: rgba(0, 0, 0, 0.3);
 $almost-black: #242424;
diff --git a/app/assets/stylesheets/new_nav.scss b/app/assets/stylesheets/new_nav.scss
index 8e095cbdd7e99e6ed7d1d8ac4f4df3d5239cd7bf..2b6c0fc015cedfc02ca0b759ed03162159e5922f 100644
--- a/app/assets/stylesheets/new_nav.scss
+++ b/app/assets/stylesheets/new_nav.scss
@@ -9,20 +9,10 @@
 
 header.navbar-gitlab-new {
   color: $white-light;
+  background: linear-gradient(to right, $indigo-900, $indigo-800);
   border-bottom: 0;
   min-height: $new-navbar-height;
 
-  .logo-text {
-    line-height: initial;
-
-    svg {
-      width: 55px;
-      height: 14px;
-      margin: 0;
-      fill: $white-light;
-    }
-  }
-
   .header-content {
     display: -webkit-flex;
     display: flex;
@@ -48,10 +38,10 @@ header.navbar-gitlab-new {
 
       img {
         height: 28px;
-        margin-right: 8px;
+        margin-right: 10px;
       }
 
-      a {
+      > a {
         display: -webkit-flex;
         display: flex;
         align-items: center;
@@ -64,6 +54,22 @@ header.navbar-gitlab-new {
             margin-right: 8px;
           }
         }
+
+        .logo-text {
+          line-height: initial;
+
+          svg {
+            width: 55px;
+            height: 14px;
+            margin: 0;
+            fill: $white-light;
+          }
+        }
+
+        &:hover,
+        &:focus {
+          background-color: rgba($indigo-200, .2);
+        }
       }
     }
 
@@ -100,6 +106,7 @@ header.navbar-gitlab-new {
 
   .navbar-collapse {
     padding-left: 0;
+    color: $indigo-200;
     box-shadow: 0;
 
     @media (max-width: $screen-xs-max) {
@@ -125,6 +132,7 @@ header.navbar-gitlab-new {
       font-size: 14px;
       text-align: center;
       color: currentColor;
+      border-left: 1px solid lighten($indigo-700, 10%);
 
       &:hover,
       &:focus,
@@ -159,41 +167,51 @@ header.navbar-gitlab-new {
         will-change: color;
         margin: 4px 2px;
         padding: 6px 8px;
+        color: $indigo-200;
         height: 32px;
 
         @media (max-width: $screen-xs-max) {
           padding: 0;
         }
 
+        svg {
+          fill: $indigo-200;
+        }
+
         &.header-user-dropdown-toggle {
           margin-left: 2px;
 
           .header-user-avatar {
+            border-color: $indigo-200;
             margin-right: 0;
           }
         }
+      }
 
-        &:hover,
-        &:focus {
-          text-decoration: none;
-          outline: 0;
-          opacity: 1;
-          color: $white-light;
+      .header-new-dropdown-toggle {
+        margin-right: 0;
+      }
 
-          svg {
-            fill: currentColor;
-          }
+      > a:hover,
+      > a:focus {
+        text-decoration: none;
+        outline: 0;
+        opacity: 1;
+        color: $white-light;
 
-          &.header-user-dropdown-toggle {
-            .header-user-avatar {
-              border-color: $white-light;
-            }
-          }
+        @media (min-width: $screen-sm-min) {
+          background-color: rgba($indigo-200, .2);
         }
-      }
 
-      .header-new-dropdown-toggle {
-        margin-right: 0;
+        svg {
+          fill: currentColor;
+        }
+
+        &.header-user-dropdown-toggle {
+          .header-user-avatar {
+            border-color: $white-light;
+          }
+        }
       }
 
       .impersonated-user,
@@ -202,6 +220,10 @@ header.navbar-gitlab-new {
         background-color: $white-light;
         border-top-right-radius: 0;
         border-bottom-right-radius: 0;
+
+        svg {
+          fill: $indigo-900;
+        }
       }
 
       .impersonation-btn,
@@ -219,6 +241,8 @@ header.navbar-gitlab-new {
 
       &.active > a,
       &.dropdown.open > a {
+        color: $indigo-900;
+        background-color: $white-light;
 
         svg {
           fill: currentColor;
@@ -232,6 +256,7 @@ header.navbar-gitlab-new {
   display: -webkit-flex;
   display: flex;
   margin: 0 0 0 6px;
+  color: $indigo-200;
 
   .dropdown-chevron {
     position: relative;
@@ -249,6 +274,17 @@ header.navbar-gitlab-new {
         text-decoration: none;
         outline: 0;
         color: $white-light;
+        background-color: rgba($indigo-200, .2);
+
+        svg {
+          fill: currentColor;
+        }
+      }
+
+      &.active > a,
+      &.dropdown.open > a {
+        color: $indigo-900;
+        background-color: $white-light;
 
         svg {
           fill: currentColor;
@@ -273,6 +309,7 @@ header.navbar-gitlab-new {
       }
 
       &.line-separator {
+        border-left: 1px solid rgba($indigo-200, .2);
         margin: 8px;
       }
     }
@@ -302,14 +339,17 @@ header.navbar-gitlab-new {
     height: 32px;
     border: 0;
     border-radius: $border-radius-default;
+    background-color: rgba($indigo-200, .2);
     transition: border-color ease-in-out 0.15s, background-color ease-in-out 0.15s;
 
     &:hover {
+      background-color: rgba($indigo-200, .3);
       box-shadow: none;
     }
   }
 
   &.search-active form {
+    background-color: $white-light;
     box-shadow: none;
 
     .search-input {
@@ -337,26 +377,43 @@ header.navbar-gitlab-new {
   }
 
   .search-input::placeholder {
+    color: rgba($indigo-200, .8);
     transition: color ease-in-out 0.15s;
   }
 
   .location-badge {
     font-size: 12px;
+    color: $indigo-100;
+    background-color: rgba($indigo-200, .1);
+    will-change: color;
     margin: -4px 4px -4px -4px;
     line-height: 25px;
     padding: 4px 8px;
     border-radius: 2px 0 0 2px;
+    border-right: 1px solid $indigo-800;
     height: 32px;
     transition: border-color ease-in-out 0.15s;
   }
 
+  .search-input-wrap {
+    .search-icon,
+    .clear-icon {
+      color: rgba($indigo-200, .8);
+    }
+  }
+
   &.search-active {
     .location-badge {
+      color: $gl-text-color;
       background-color: $nav-badge-bg;
       border-color: $border-color;
     }
 
     .search-input-wrap {
+      .search-icon {
+        color: rgba($indigo-200, .8);
+      }
+
       .clear-icon {
         color: $white-light;
       }
@@ -460,6 +517,8 @@ header.navbar-gitlab-new {
 
 .btn-sign-in {
   margin-top: 3px;
+  background-color: $indigo-100;
+  color: $indigo-900;
   font-weight: $gl-font-weight-bold;
 
   &:hover {
diff --git a/app/assets/stylesheets/new_sidebar.scss b/app/assets/stylesheets/new_sidebar.scss
index 4bbd30056a9dab9810c20e26d8417a62ffa2b32c..3082f728ac835dd4331ccd7df78208a424e4f669 100644
--- a/app/assets/stylesheets/new_sidebar.scss
+++ b/app/assets/stylesheets/new_sidebar.scss
@@ -155,9 +155,16 @@ $new-sidebar-collapsed-width: 50px;
   }
 
   li.active {
+    box-shadow: inset 4px 0 0 $active-border;
+
     > a {
+      color: $active-color;
       font-weight: $gl-font-weight-bold;
     }
+
+    svg {
+      fill: $active-color;
+    }
   }
 
   @media (max-width: $screen-xs-max) {
diff --git a/app/assets/stylesheets/pages/profiles/preferences.scss b/app/assets/stylesheets/pages/profiles/preferences.scss
index c197494b152507a67fb84cdf8fec714e065bae8a..305feaacaa15a4b38f01fbd2cd74836f4c130a45 100644
--- a/app/assets/stylesheets/pages/profiles/preferences.scss
+++ b/app/assets/stylesheets/pages/profiles/preferences.scss
@@ -1,67 +1,3 @@
-@mixin application-theme-preview($color-1, $color-2, $color-3, $color-4) {
-  .one {
-    background-color: $color-1;
-    border-top-left-radius: $border-radius-default;
-  }
-
-  .two {
-    background-color: $color-2;
-    border-top-right-radius: $border-radius-default;
-  }
-
-  .three {
-    background-color: $color-3;
-    border-bottom-left-radius: $border-radius-default;
-  }
-
-  .four {
-    background-color: $color-4;
-    border-bottom-right-radius: $border-radius-default;
-  }
-}
-
-.application-theme {
-  label {
-    margin-right: 20px;
-    text-align: center;
-  }
-
-  .preview {
-    font-size: 0;
-    margin-bottom: 10px;
-
-    &.indigo {
-      @include application-theme-preview($indigo-900, $indigo-700, $indigo-800, $indigo-500);
-    }
-
-    &.dark {
-      @include application-theme-preview($theme-gray-900, $theme-gray-700, $theme-gray-800, $theme-gray-600);
-    }
-
-    &.light {
-      @include application-theme-preview($theme-gray-600, $theme-gray-200, $theme-gray-400, $theme-gray-100);
-    }
-
-    &.blue {
-      @include application-theme-preview($theme-blue-900, $theme-blue-700, $theme-blue-800, $theme-blue-500);
-    }
-
-    &.green {
-      @include application-theme-preview($theme-green-900, $theme-green-700, $theme-green-800, $theme-green-500);
-    }
-  }
-
-  .preview-row {
-    display: block;
-  }
-
-  .quadrant {
-    display: inline-block;
-    height: 50px;
-    width: 80px;
-  }
-}
-
 .syntax-theme {
   label {
     margin-right: 20px;
diff --git a/app/controllers/admin/users_controller.rb b/app/controllers/admin/users_controller.rb
index cbcef70e957158248171bc6d2dab36e2ae0e4cd1..9ec7719fabbfec3d9741e1eaa67d8c3b37e4858a 100644
--- a/app/controllers/admin/users_controller.rb
+++ b/app/controllers/admin/users_controller.rb
@@ -211,7 +211,6 @@ class Admin::UsersController < Admin::ApplicationController
       :provider,
       :remember_me,
       :skype,
-      :theme_id,
       :twitter,
       :username,
       :website_url
diff --git a/app/controllers/profiles/preferences_controller.rb b/app/controllers/profiles/preferences_controller.rb
index cce2a847b53890385e4be6a99cabffe447c6fc64..1e557c476384426d04cc35ef5f92b92bf50bb7f6 100644
--- a/app/controllers/profiles/preferences_controller.rb
+++ b/app/controllers/profiles/preferences_controller.rb
@@ -35,8 +35,7 @@ class Profiles::PreferencesController < Profiles::ApplicationController
       :color_scheme_id,
       :layout,
       :dashboard,
-      :project_view,
-      :theme_id
+      :project_view
     )
   end
 end
diff --git a/app/helpers/preferences_helper.rb b/app/helpers/preferences_helper.rb
index 0d7347ed30d66c38136c62375eebfd988de81ac4..d36bb4ab07495fc706d539388d3ddfe661bfba84 100644
--- a/app/helpers/preferences_helper.rb
+++ b/app/helpers/preferences_helper.rb
@@ -40,10 +40,6 @@ module PreferencesHelper
     ]
   end
 
-  def user_application_theme
-    @user_application_theme ||= Gitlab::Themes.for_user(current_user).css_class
-  end
-
   def user_color_scheme
     Gitlab::ColorSchemes.for_user(current_user).css_class
   end
diff --git a/app/models/user.rb b/app/models/user.rb
index d7549409b15577104938ce0cd3289c1fe46f3a1b..26b14ade5ca77371d485f59ff289fff8d9c476de 100644
--- a/app/models/user.rb
+++ b/app/models/user.rb
@@ -35,7 +35,6 @@ class User < ActiveRecord::Base
   default_value_for :project_view, :files
   default_value_for :notified_of_own_activity, false
   default_value_for :preferred_language, I18n.default_locale
-  default_value_for :theme_id, gitlab_config.default_theme
 
   attr_encrypted :otp_secret,
     key:       Gitlab::Application.secrets.otp_key_base,
diff --git a/app/views/layouts/application.html.haml b/app/views/layouts/application.html.haml
index 0ca34b276a71f202b3bd21eda0efaffecb2c9f1d..65ac8aaa59b629bf83de943a3a0f026e2a1ea516 100644
--- a/app/views/layouts/application.html.haml
+++ b/app/views/layouts/application.html.haml
@@ -1,7 +1,7 @@
 !!! 5
 %html{ lang: I18n.locale, class: page_class }
   = render "layouts/head"
-  %body{ class: "#{user_application_theme} #{@body_class}", data: { page: body_data_page, project: "#{@project.path if @project}", group: "#{@group.path if @group}", find_file: find_file_path } }
+  %body{ class: @body_class, data: { page: body_data_page, project: "#{@project.path if @project}", group: "#{@group.path if @group}", find_file: find_file_path } }
     = render "layouts/init_auto_complete" if @gfm_form
     = render 'peek/bar'
     = render "layouts/header/default"
diff --git a/app/views/profiles/preferences/show.html.haml b/app/views/profiles/preferences/show.html.haml
index 2b72eeab8d66f9084b58297cf2fbcd1cc3dd4c3e..9e7fe556d88a17664e282a0636d1e132de24ca83 100644
--- a/app/views/profiles/preferences/show.html.haml
+++ b/app/views/profiles/preferences/show.html.haml
@@ -3,26 +3,6 @@
 = render 'profiles/head'
 
 = form_for @user, url: profile_preferences_path, remote: true, method: :put, html: { class: 'row prepend-top-default js-preferences-form' } do |f|
-  .col-lg-4.application-theme
-    %h4.prepend-top-0
-      GitLab navigation theme
-    %p Customize the appearance of the application header and navigation sidebar.
-  .col-lg-8.application-theme
-    - Gitlab::Themes.each do |theme|
-      = label_tag do
-        .preview{ class: theme.name.downcase }
-          .preview-row
-            .quadrant.one
-            .quadrant.two
-          .preview-row
-            .quadrant.three
-            .quadrant.four
-        = f.radio_button :theme_id, theme.id
-        = theme.name
-
-  .col-sm-12
-    %hr
-
   .col-lg-4.profile-settings-sidebar
     %h4.prepend-top-0
       Syntax highlighting theme
diff --git a/app/views/profiles/preferences/update.js.erb b/app/views/profiles/preferences/update.js.erb
index 8966dd3fd862fe8bc3dd4c4c20a6fcb84375fa86..431ab9d052b989fedd2bff41f6c568f17054dbc9 100644
--- a/app/views/profiles/preferences/update.js.erb
+++ b/app/views/profiles/preferences/update.js.erb
@@ -1,7 +1,3 @@
-// Remove body class for any previous theme, re-add current one
-$('body').removeClass('<%= Gitlab::Themes.body_classes %>')
-$('body').addClass('<%= user_application_theme %>')
-
 // Toggle container-fluid class
 if ('<%= current_user.layout %>' === 'fluid') {
   $('.content-wrapper .container-fluid').removeClass('container-limited')
diff --git a/changelogs/unreleased/35012-navigation-add-option-to-change-navigation-color-palette.yml b/changelogs/unreleased/35012-navigation-add-option-to-change-navigation-color-palette.yml
deleted file mode 100644
index 74aa337a18c83f01712f5e492dd3caf79d971bc9..0000000000000000000000000000000000000000
--- a/changelogs/unreleased/35012-navigation-add-option-to-change-navigation-color-palette.yml
+++ /dev/null
@@ -1,5 +0,0 @@
----
-title: Add option in preferences to change navigation theme color
-merge_request:
-author:
-type: added
diff --git a/config/gitlab.yml.example b/config/gitlab.yml.example
index cd44f888d3f0738d6eb4e45c99c80e0c79d8c231..e96610908448e5c3be88c82994410ef690db746f 100644
--- a/config/gitlab.yml.example
+++ b/config/gitlab.yml.example
@@ -76,13 +76,6 @@ production: &base
 
     # default_can_create_group: false  # default: true
     # username_changing_enabled: false # default: true - User can change her username/namespace
-    ## Default theme ID
-    ##   1 - Indigo
-    ##   2 - Dark
-    ##   3 - Light
-    ##   4 - Blue
-    ##   5 - Green
-    # default_theme: 1 # default: 1
 
     ## Automatic issue closing
     # If a commit message matches this regular expression, all issues referenced from the matched text will be closed.
diff --git a/config/initializers/1_settings.rb b/config/initializers/1_settings.rb
index 40fbdd3ef9b748f2f37cebea2028351a7848a5b5..7c1ca05a57b7e068b78468ca0eb5b6cdd495d58c 100644
--- a/config/initializers/1_settings.rb
+++ b/config/initializers/1_settings.rb
@@ -232,7 +232,6 @@ Settings['gitlab'] ||= Settingslogic.new({})
 Settings.gitlab['default_projects_limit'] ||= 100000
 Settings.gitlab['default_branch_protection'] ||= 2
 Settings.gitlab['default_can_create_group'] = true if Settings.gitlab['default_can_create_group'].nil?
-Settings.gitlab['default_theme'] = Gitlab::Themes::APPLICATION_DEFAULT if Settings.gitlab['default_theme'].nil?
 Settings.gitlab['host']       ||= ENV['GITLAB_HOST'] || 'localhost'
 Settings.gitlab['ssh_host']   ||= Settings.gitlab.host
 Settings.gitlab['https']        = false if Settings.gitlab['https'].nil?
diff --git a/db/migrate/20170816234252_add_theme_id_to_users.rb b/db/migrate/20170816234252_add_theme_id_to_users.rb
deleted file mode 100644
index 5043f9ec5917433ce5a76d189434834c3b7f5188..0000000000000000000000000000000000000000
--- a/db/migrate/20170816234252_add_theme_id_to_users.rb
+++ /dev/null
@@ -1,10 +0,0 @@
-# See http://doc.gitlab.com/ce/development/migration_style_guide.html
-# for more information on how to write migrations for GitLab.
-
-class AddThemeIdToUsers < ActiveRecord::Migration
-  DOWNTIME = false
-
-  def change
-    add_column :users, :theme_id, :integer, limit: 2
-  end
-end
diff --git a/db/schema.rb b/db/schema.rb
index 2149f5ad23df0a8d17a55115c59bf6b6403a5605..df941afa7d70da98d223b48c039fb8e2ba20414d 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -1608,7 +1608,6 @@ ActiveRecord::Schema.define(version: 20170905112933) do
     t.boolean "notified_of_own_activity"
     t.string "preferred_language"
     t.string "rss_token"
-    t.integer "theme_id", limit: 2
   end
 
   add_index "users", ["admin"], name: "index_users_on_admin", using: :btree
diff --git a/doc/api/keys.md b/doc/api/keys.md
index ddcf7830621444aa2a9e68906c79ff6dc3024715..376ac27df3a2ea4e07c3b45edb8ad08d8ebb32d3 100644
--- a/doc/api/keys.md
+++ b/doc/api/keys.md
@@ -32,7 +32,6 @@ Parameters:
     "twitter": "",
     "website_url": "",
     "email": "john@example.com",
-    "theme_id": 2,
     "color_scheme_id": 1,
     "projects_limit": 10,
     "current_sign_in_at": null,
diff --git a/doc/api/session.md b/doc/api/session.md
index b97e26f34a2c71b88aaf3e9f664327a76bf221ac..f79eac11689f4fe68de2162ad74e048db87fc91e 100644
--- a/doc/api/session.md
+++ b/doc/api/session.md
@@ -39,7 +39,6 @@ Example response:
   "twitter": "",
   "website_url": "",
   "email": "john@example.com",
-  "theme_id": 1,
   "color_scheme_id": 1,
   "projects_limit": 10,
   "current_sign_in_at": "2015-07-07T07:10:58.392Z",
diff --git a/doc/api/users.md b/doc/api/users.md
index 6d5db16b36ad15e28abdc8dc7603460a2c6a1b72..9f3e4caf2f476dd01d36c843eeefa3fc6ca11544 100644
--- a/doc/api/users.md
+++ b/doc/api/users.md
@@ -72,7 +72,6 @@ GET /users
     "organization": "",
     "last_sign_in_at": "2012-06-01T11:41:01Z",
     "confirmed_at": "2012-05-23T09:05:22Z",
-    "theme_id": 1,
     "last_activity_on": "2012-05-23",
     "color_scheme_id": 2,
     "projects_limit": 100,
@@ -106,7 +105,6 @@ GET /users
     "organization": "",
     "last_sign_in_at": null,
     "confirmed_at": "2012-05-30T16:53:06.148Z",
-    "theme_id": 1,
     "last_activity_on": "2012-05-23",
     "color_scheme_id": 3,
     "projects_limit": 100,
@@ -217,7 +215,6 @@ Parameters:
   "organization": "",
   "last_sign_in_at": "2012-06-01T11:41:01Z",
   "confirmed_at": "2012-05-23T09:05:22Z",
-  "theme_id": 1,
   "last_activity_on": "2012-05-23",
   "color_scheme_id": 2,
   "projects_limit": 100,
@@ -344,7 +341,6 @@ GET /user
   "organization": "",
   "last_sign_in_at": "2012-06-01T11:41:01Z",
   "confirmed_at": "2012-05-23T09:05:22Z",
-  "theme_id": 1,
   "last_activity_on": "2012-05-23",
   "color_scheme_id": 2,
   "projects_limit": 100,
@@ -391,7 +387,6 @@ GET /user
   "organization": "",
   "last_sign_in_at": "2012-06-01T11:41:01Z",
   "confirmed_at": "2012-05-23T09:05:22Z",
-  "theme_id": 1,
   "last_activity_on": "2012-05-23",
   "color_scheme_id": 2,
   "projects_limit": 100,
diff --git a/lib/api/entities.rb b/lib/api/entities.rb
index 52c49e5caa998e6aa9440127aa43e84b9fd4c8c7..216408064d18a3b122434a3e3cdf16765aa4629f 100644
--- a/lib/api/entities.rb
+++ b/lib/api/entities.rb
@@ -45,7 +45,7 @@ module API
       expose :confirmed_at
       expose :last_activity_on
       expose :email
-      expose :theme_id, :color_scheme_id, :projects_limit, :current_sign_in_at
+      expose :color_scheme_id, :projects_limit, :current_sign_in_at
       expose :identities, using: Entities::Identity
       expose :can_create_group?, as: :can_create_group
       expose :can_create_project?, as: :can_create_project
diff --git a/lib/gitlab/themes.rb b/lib/gitlab/themes.rb
deleted file mode 100644
index d43eff5ba4a04c93cd7774f23a627b06245809b3..0000000000000000000000000000000000000000
--- a/lib/gitlab/themes.rb
+++ /dev/null
@@ -1,84 +0,0 @@
-module Gitlab
-  # Module containing GitLab's application theme definitions and helper methods
-  # for accessing them.
-  module Themes
-    extend self
-
-    # Theme ID used when no `default_theme` configuration setting is provided.
-    APPLICATION_DEFAULT = 1
-
-    # Struct class representing a single Theme
-    Theme = Struct.new(:id, :name, :css_class)
-
-    # All available Themes
-    THEMES = [
-      Theme.new(1, 'Indigo', 'ui_indigo'),
-      Theme.new(2, 'Dark', 'ui_dark'),
-      Theme.new(3, 'Light', 'ui_light'),
-      Theme.new(4, 'Blue', 'ui_blue'),
-      Theme.new(5, 'Green', 'ui_green')
-    ].freeze
-
-    # Convenience method to get a space-separated String of all the theme
-    # classes that might be applied to the `body` element
-    #
-    # Returns a String
-    def body_classes
-      THEMES.collect(&:css_class).uniq.join(' ')
-    end
-
-    # Get a Theme by its ID
-    #
-    # If the ID is invalid, returns the default Theme.
-    #
-    # id - Integer ID
-    #
-    # Returns a Theme
-    def by_id(id)
-      THEMES.detect { |t| t.id == id } || default
-    end
-
-    # Returns the number of defined Themes
-    def count
-      THEMES.size
-    end
-
-    # Get the default Theme
-    #
-    # Returns a Theme
-    def default
-      by_id(default_id)
-    end
-
-    # Iterate through each Theme
-    #
-    # Yields the Theme object
-    def each(&block)
-      THEMES.each(&block)
-    end
-
-    # Get the Theme for the specified user, or the default
-    #
-    # user - User record
-    #
-    # Returns a Theme
-    def for_user(user)
-      if user
-        by_id(user.theme_id)
-      else
-        default
-      end
-    end
-
-    private
-
-    def default_id
-      @default_id ||= begin
-        id = Gitlab.config.gitlab.default_theme.to_i
-        theme_ids = THEMES.map(&:id)
-
-        theme_ids.include?(id) ? id : APPLICATION_DEFAULT
-      end
-    end
-  end
-end
diff --git a/spec/controllers/profiles/preferences_controller_spec.rb b/spec/controllers/profiles/preferences_controller_spec.rb
index a66b4ab09022454ddceb7b309b7fd0c15b6885e4..a5f544b4f9225eab6ae6193eee4e095550f606bb 100644
--- a/spec/controllers/profiles/preferences_controller_spec.rb
+++ b/spec/controllers/profiles/preferences_controller_spec.rb
@@ -25,8 +25,7 @@ describe Profiles::PreferencesController do
     def go(params: {}, format: :js)
       params.reverse_merge!(
         color_scheme_id: '1',
-        dashboard: 'stars',
-        theme_id: '1'
+        dashboard: 'stars'
       )
 
       patch :update, user: params, format: format
@@ -41,8 +40,7 @@ describe Profiles::PreferencesController do
       it "changes the user's preferences" do
         prefs = {
           color_scheme_id: '1',
-          dashboard: 'stars',
-          theme_id: '2'
+          dashboard: 'stars'
         }.with_indifferent_access
 
         expect(user).to receive(:assign_attributes).with(prefs)
diff --git a/spec/fixtures/api/schemas/public_api/v4/user/login.json b/spec/fixtures/api/schemas/public_api/v4/user/login.json
index e6c1d9c9d845ab527f03a768f4c98a60ace92d20..6181b3ccc8694545c49994cacfc80002688c4fbe 100644
--- a/spec/fixtures/api/schemas/public_api/v4/user/login.json
+++ b/spec/fixtures/api/schemas/public_api/v4/user/login.json
@@ -19,7 +19,6 @@
     "organization",
     "last_sign_in_at",
     "confirmed_at",
-    "theme_id",
     "color_scheme_id",
     "projects_limit",
     "current_sign_in_at",
diff --git a/spec/helpers/preferences_helper_spec.rb b/spec/helpers/preferences_helper_spec.rb
index 8b8080563d342273e14c4255f88a51a995479508..a04c87b08eb77c1f8c06411c2c5d4c622bb2d125 100644
--- a/spec/helpers/preferences_helper_spec.rb
+++ b/spec/helpers/preferences_helper_spec.rb
@@ -1,7 +1,7 @@
 require 'spec_helper'
 
 describe PreferencesHelper do
-  describe '#dashboard_choices' do
+  describe 'dashboard_choices' do
     it 'raises an exception when defined choices may be missing' do
       expect(User).to receive(:dashboards).and_return(foo: 'foo')
       expect { helper.dashboard_choices }.to raise_error(RuntimeError)
@@ -26,33 +26,7 @@ describe PreferencesHelper do
     end
   end
 
-  describe '#user_application_theme' do
-    context 'with a user' do
-      it "returns user's theme's css_class" do
-        stub_user(theme_id: 3)
-
-        expect(helper.user_application_theme).to eq 'ui_light'
-      end
-
-      it 'returns the default when id is invalid' do
-        stub_user(theme_id: Gitlab::Themes.count + 5)
-
-        allow(Gitlab.config.gitlab).to receive(:default_theme).and_return(1)
-
-        expect(helper.user_application_theme).to eq 'ui_indigo'
-      end
-    end
-
-    context 'without a user' do
-      it 'returns the default theme' do
-        stub_user
-
-        expect(helper.user_application_theme).to eq Gitlab::Themes.default.css_class
-      end
-    end
-  end
-
-  describe '#user_color_scheme' do
+  describe 'user_color_scheme' do
     context 'with a user' do
       it "returns user's scheme's css_class" do
         allow(helper).to receive(:current_user)
diff --git a/spec/lib/gitlab/background_migration/migrate_events_to_push_event_payloads_spec.rb b/spec/lib/gitlab/background_migration/migrate_events_to_push_event_payloads_spec.rb
index cb52d971047060d0bd53c8a05ca6fdbd1d7cf02e..b155c20d8d3e4971d8ca365ea4139fceb2e427f0 100644
--- a/spec/lib/gitlab/background_migration/migrate_events_to_push_event_payloads_spec.rb
+++ b/spec/lib/gitlab/background_migration/migrate_events_to_push_event_payloads_spec.rb
@@ -215,17 +215,9 @@ end
 # to a specific version of the database where said table is still present.
 #
 describe Gitlab::BackgroundMigration::MigrateEventsToPushEventPayloads, :migration, schema: 20170825154015 do
-  let(:user_class) do
-    Class.new(ActiveRecord::Base) do
-      self.table_name = 'users'
-    end
-  end
-
   let(:migration) { described_class.new }
-  let(:user_class) { table(:users) }
-  let(:author) { build(:user).becomes(user_class).tap(&:save!).becomes(User) }
-  let(:namespace) { create(:namespace, owner: author) }
-  let(:project) { create(:project_empty_repo, namespace: namespace, creator: author) }
+  let(:project) { create(:project_empty_repo) }
+  let(:author) { create(:user) }
 
   # We can not rely on FactoryGirl as the state of Event may change in ways that
   # the background migration does not expect, hence we use the Event class of
diff --git a/spec/lib/gitlab/themes_spec.rb b/spec/lib/gitlab/themes_spec.rb
deleted file mode 100644
index ecacea6bb3528f9a402cc40c9017ac727d183615..0000000000000000000000000000000000000000
--- a/spec/lib/gitlab/themes_spec.rb
+++ /dev/null
@@ -1,48 +0,0 @@
-require 'spec_helper'
-
-describe Gitlab::Themes, lib: true do
-  describe '.body_classes' do
-    it 'returns a space-separated list of class names' do
-      css = described_class.body_classes
-
-      expect(css).to include('ui_indigo')
-      expect(css).to include(' ui_dark ')
-      expect(css).to include(' ui_blue')
-    end
-  end
-
-  describe '.by_id' do
-    it 'returns a Theme by its ID' do
-      expect(described_class.by_id(1).name).to eq 'Indigo'
-      expect(described_class.by_id(3).name).to eq 'Light'
-    end
-  end
-
-  describe '.default' do
-    it 'returns the default application theme' do
-      allow(described_class).to receive(:default_id).and_return(2)
-      expect(described_class.default.id).to eq 2
-    end
-
-    it 'prevents an infinite loop when configuration default is invalid' do
-      default = described_class::APPLICATION_DEFAULT
-      themes  = described_class::THEMES
-
-      config = double(default_theme: 0).as_null_object
-      allow(Gitlab).to receive(:config).and_return(config)
-      expect(described_class.default.id).to eq default
-
-      config = double(default_theme: themes.size + 5).as_null_object
-      allow(Gitlab).to receive(:config).and_return(config)
-      expect(described_class.default.id).to eq default
-    end
-  end
-
-  describe '.each' do
-    it 'passes the block to the THEMES Array' do
-      ids = []
-      described_class.each { |theme| ids << theme.id }
-      expect(ids).not_to be_empty
-    end
-  end
-end
diff --git a/spec/migrations/convert_custom_notification_settings_to_columns_spec.rb b/spec/migrations/convert_custom_notification_settings_to_columns_spec.rb
index 759e77ac9db72400eefbbe68e31a88cad02ddccd..1396d12e5a9cba39153ceb721df1c4fe6206b8ef 100644
--- a/spec/migrations/convert_custom_notification_settings_to_columns_spec.rb
+++ b/spec/migrations/convert_custom_notification_settings_to_columns_spec.rb
@@ -2,8 +2,6 @@ require 'spec_helper'
 require Rails.root.join('db', 'post_migrate', '20170607121233_convert_custom_notification_settings_to_columns')
 
 describe ConvertCustomNotificationSettingsToColumns, :migration do
-  let(:user_class) { table(:users) }
-
   let(:settings_params) do
     [
       { level: 0, events: [:new_note] }, # disabled, single event
@@ -21,7 +19,7 @@ describe ConvertCustomNotificationSettingsToColumns, :migration do
         events[event] = true
       end
 
-      user = build(:user).becomes(user_class).tap(&:save!)
+      user = create(:user)
       create_params = { user_id: user.id, level: params[:level], events: events }
       notification_setting = described_class::NotificationSetting.create(create_params)
 
@@ -37,7 +35,7 @@ describe ConvertCustomNotificationSettingsToColumns, :migration do
         events[event] = true
       end
 
-      user = build(:user).becomes(user_class).tap(&:save!)
+      user = create(:user)
       create_params = events.merge(user_id: user.id, level: params[:level])
       notification_setting = described_class::NotificationSetting.create(create_params)
 
diff --git a/spec/models/user_spec.rb b/spec/models/user_spec.rb
index 73a1e47149cbf0509ac72ec7e50e7ecd59d538c0..36d1f6f3644887f4b865efabad434c6568b707a1 100644
--- a/spec/models/user_spec.rb
+++ b/spec/models/user_spec.rb
@@ -716,7 +716,6 @@ describe User do
       it "applies defaults to user" do
         expect(user.projects_limit).to eq(Gitlab.config.gitlab.default_projects_limit)
         expect(user.can_create_group).to eq(Gitlab.config.gitlab.default_can_create_group)
-        expect(user.theme_id).to eq(Gitlab.config.gitlab.default_theme)
         expect(user.external).to be_falsey
       end
     end
@@ -727,7 +726,6 @@ describe User do
       it "applies defaults to user" do
         expect(user.projects_limit).to eq(123)
         expect(user.can_create_group).to be_falsey
-        expect(user.theme_id).to eq(1)
       end
     end
 
diff --git a/spec/support/gitlab_stubs/session.json b/spec/support/gitlab_stubs/session.json
index 688175369ae5bdea2f471b80740e87716d24244b..cd55d63125e5975316bf1504b1a9192d1c278039 100644
--- a/spec/support/gitlab_stubs/session.json
+++ b/spec/support/gitlab_stubs/session.json
@@ -7,7 +7,7 @@
   "skype":"aertert",
   "linkedin":"",
   "twitter":"",
-  "theme_id":2,"color_scheme_id":2,
+  "color_scheme_id":2,
   "state":"active",
   "created_at":"2012-12-21T13:02:20Z",
   "extern_uid":null,
diff --git a/spec/support/gitlab_stubs/user.json b/spec/support/gitlab_stubs/user.json
index ce8dfe5ae7559b755a4735f36c93b146cc8430bc..cd55d63125e5975316bf1504b1a9192d1c278039 100644
--- a/spec/support/gitlab_stubs/user.json
+++ b/spec/support/gitlab_stubs/user.json
@@ -7,7 +7,7 @@
   "skype":"aertert",
   "linkedin":"",
   "twitter":"",
-  "theme_id":2,"color_scheme_id":2,
+  "color_scheme_id":2,
   "state":"active",
   "created_at":"2012-12-21T13:02:20Z",
   "extern_uid":null,
@@ -17,4 +17,4 @@
   "can_create_project":false,
   "private_token":"Wvjy2Krpb7y8xi93owUz",
   "access_token":"Wvjy2Krpb7y8xi93owUz"
-}
\ No newline at end of file
+}