fix #36674

src/vs/base/browser/ui/splitview/panelview.ts

@@ -27,7 +27,7 @@ export interface IPanelStyles {
 	dropBackground?: Color;
 	headerForeground?: Color;
 	headerBackground?: Color;
-	headerHighContrastBorder?: Color;
+	headerBorder?: Color;
 }
 
 /**
@@ -218,7 +218,7 @@ export abstract class Panel implements IView {
 
 		this.header.style.color = this.styles.headerForeground ? this.styles.headerForeground.toString() : null;
 		this.header.style.backgroundColor = this.styles.headerBackground ? this.styles.headerBackground.toString() : null;
-		this.header.style.borderTop = this.styles.headerHighContrastBorder ? `1px solid ${this.styles.headerHighContrastBorder}` : null;
+		this.header.style.borderTop = this.styles.headerBorder ? `1px solid ${this.styles.headerBorder}` : null;
 		this._dropBackground = this.styles.dropBackground;
 	}
 

src/vs/workbench/browser/parts/views/panelViewlet.ts

@@ -7,9 +7,9 @@ import 'vs/css!./media/panelviewlet';
 import * as nls from 'vs/nls';
 import { TPromise } from 'vs/base/common/winjs.base';
 import { Event, Emitter, filterEvent } from 'vs/base/common/event';
-import { ColorIdentifier, contrastBorder } from 'vs/platform/theme/common/colorRegistry';
+import { ColorIdentifier } from 'vs/platform/theme/common/colorRegistry';
 import { attachStyler, IColorMapping } from 'vs/platform/theme/common/styler';
-import { SIDE_BAR_DRAG_AND_DROP_BACKGROUND, SIDE_BAR_SECTION_HEADER_FOREGROUND, SIDE_BAR_SECTION_HEADER_BACKGROUND } from 'vs/workbench/common/theme';
+import { SIDE_BAR_DRAG_AND_DROP_BACKGROUND, SIDE_BAR_SECTION_HEADER_FOREGROUND, SIDE_BAR_SECTION_HEADER_BACKGROUND, SIDE_BAR_SECTION_HEADER_BORDER } from 'vs/workbench/common/theme';
 import { append, $, trackFocus, toggleClass, EventType, isAncestor, Dimension, addDisposableListener } from 'vs/base/browser/dom';
 import { IDisposable, combinedDisposable } from 'vs/base/common/lifecycle';
 import { firstIndex } from 'vs/base/common/arrays';
@@ -33,7 +33,7 @@ export interface IPanelColors extends IColorMapping {
 	dropBackground?: ColorIdentifier;
 	headerForeground?: ColorIdentifier;
 	headerBackground?: ColorIdentifier;
-	headerHighContrastBorder?: ColorIdentifier;
+	headerBorder?: ColorIdentifier;
 }
 
 export interface IViewletPanelOptions extends IPanelOptions {
@@ -323,7 +323,7 @@ export class PanelViewlet extends Viewlet {
 		const panelStyler = attachStyler<IPanelColors>(this.themeService, {
 			headerForeground: SIDE_BAR_SECTION_HEADER_FOREGROUND,
 			headerBackground: SIDE_BAR_SECTION_HEADER_BACKGROUND,
-			headerHighContrastBorder: index === 0 ? null : contrastBorder,
+			headerBorder: index === 0 ? null : SIDE_BAR_SECTION_HEADER_BORDER,
 			dropBackground: SIDE_BAR_DRAG_AND_DROP_BACKGROUND
 		}, panel);
 		const disposable = combinedDisposable([onDidFocus, onDidChangeTitleArea, panelStyler, onDidChange]);

src/vs/workbench/common/theme.ts

@@ -360,6 +360,11 @@ export const SIDE_BAR_SECTION_HEADER_FOREGROUND = registerColor('sideBarSectionH
 	hc: SIDE_BAR_FOREGROUND
 }, nls.localize('sideBarSectionHeaderForeground', "Side bar section header foreground color. The side bar is the container for views like explorer and search."));
 
+export const SIDE_BAR_SECTION_HEADER_BORDER = registerColor('sideBarSectionHeader.border', {
+	dark: contrastBorder,
+	light: contrastBorder,
+	hc: contrastBorder
+}, nls.localize('sideBarSectionHeaderBorder', "Side bar section header border color. The side bar is the container for views like explorer and search."));
 
 
 // < --- Title Bar --- >