Do not use `mix-blend-mode: difference` for `hc-black`

src/vs/editor/browser/viewParts/lines/viewLine.ts

@@ -149,7 +149,7 @@ export class ViewLine implements IVisibleLine {
 		this._options = newOptions;
 	}
 	public onSelectionChanged(): boolean {
-		if (alwaysRenderInlineSelection) {
+		if (alwaysRenderInlineSelection || this._options.themeType === HIGH_CONTRAST) {
 			this._isMaybeInvalid = true;
 			return true;
 		}

src/vs/editor/browser/viewParts/selections/selections.ts

@@ -7,7 +7,7 @@
 
 import 'vs/css!./selections';
 import { registerThemingParticipant } from 'vs/platform/theme/common/themeService';
-import { editorSelection, editorInactiveSelection, activeContrastBorder } from 'vs/platform/theme/common/colorRegistry';
+import { editorSelectionBackground, editorInactiveSelection, editorSelectionForeground } from 'vs/platform/theme/common/colorRegistry';
 import { DynamicViewOverlay } from 'vs/editor/browser/view/dynamicViewOverlay';
 import { ViewContext } from 'vs/editor/common/view/viewContext';
 import { HorizontalRange, LineVisibleRanges, RenderingContext } from 'vs/editor/common/view/renderingContext';
@@ -394,7 +394,7 @@ export class SelectionsOverlay extends DynamicViewOverlay {
 }
 
 registerThemingParticipant((theme, collector) => {
-	let editorSelectionColor = theme.getColor(editorSelection);
+	let editorSelectionColor = theme.getColor(editorSelectionBackground);
 	if (editorSelectionColor) {
 		collector.addRule(`.monaco-editor .focused .selected-text { background-color: ${editorSelectionColor}; }`);
 	}
@@ -402,10 +402,8 @@ registerThemingParticipant((theme, collector) => {
 	if (editorInactiveSelectionColor) {
 		collector.addRule(`.monaco-editor .selected-text { background-color: ${editorInactiveSelectionColor}; }`);
 	}
-	// IE/Edge specific rules
-	let outline = theme.getColor(activeContrastBorder);
-	if (outline) {
-		collector.addRule(`.monaco-editor.ie.hc-black .view-overlays.focused	.selected-text { background: none; border: 2px solid ${outline}; }`);
-		collector.addRule(`.monaco-editor.edge.hc-black	.view-overlays.focused	.selected-text { background: none; border: 2px solid ${outline}; }`);
+	let editorSelectionForegroundColor = theme.getColor(editorSelectionForeground);
+	if (editorSelectionForegroundColor) {
+		collector.addRule(`.monaco-editor .view-line span.inline-selected-text { color: ${editorSelectionForegroundColor}; }`);
 	}
-});
\ No newline at end of file
+});

src/vs/editor/browser/widget/media/tokens.css

@@ -6,6 +6,4 @@
 .monaco-editor .vs-whitespace {
 	display:inline-block;
 }
-.monaco-editor.hc-black .view-line {
-	mix-blend-mode: difference;
-}
+

src/vs/platform/theme/common/colorRegistry.ts

@@ -219,9 +219,10 @@ export const editorWidgetBorder = registerColor('editorWidget.border', { dark: '
 /**
  * Editor selection colors.
  */
-export const editorSelection = registerColor('editor.selectionBackground', { light: '#ADD6FF', dark: '#264F78', hc: '#f3f518' }, nls.localize('editorSelection', "Color of the editor selection."));
-export const editorInactiveSelection = registerColor('editor.inactiveSelectionBackground', { light: transparent(editorSelection, 0.5), dark: transparent(editorSelection, 0.5), hc: null }, nls.localize('editorInactiveSelection', "Color of the selection in an inactive editor."));
-export const editorSelectionHighlight = registerColor('editor.selectionHighlightBackground', { light: lessProminent(editorSelection, editorBackground, 0.3, 0.6), dark: lessProminent(editorSelection, editorBackground, 0.3, 0.6), hc: null }, nls.localize('editorSelectionHighlight', 'Color for regions with the same content as the selection.'));
+export const editorSelectionBackground = registerColor('editor.selectionBackground', { light: '#ADD6FF', dark: '#264F78', hc: '#f3f518' }, nls.localize('editorSelectionBackground', "Color of the editor selection."));
+export const editorSelectionForeground = registerColor('editor.selectionForeground', { light: null, dark: null, hc: '#000000' }, nls.localize('editorSelectionForeground', "Color of the selected text for high contrast."));
+export const editorInactiveSelection = registerColor('editor.inactiveSelectionBackground', { light: transparent(editorSelectionBackground, 0.5), dark: transparent(editorSelectionBackground, 0.5), hc: transparent(editorSelectionBackground, 0.5) }, nls.localize('editorInactiveSelection', "Color of the selection in an inactive editor."));
+export const editorSelectionHighlight = registerColor('editor.selectionHighlightBackground', { light: lessProminent(editorSelectionBackground, editorBackground, 0.3, 0.6), dark: lessProminent(editorSelectionBackground, editorBackground, 0.3, 0.6), hc: null }, nls.localize('editorSelectionHighlight', 'Color for regions with the same content as the selection.'));
 
 /**
  * Editor find match colors.

src/vs/workbench/services/themes/electron-browser/themeCompatibility.ts

@@ -53,7 +53,7 @@ export function convertSettings(oldSettings: ITokenColorizationRule[], resultRul
 
 addSettingMapping('background', colorRegistry.editorBackground);
 addSettingMapping('foreground', colorRegistry.editorForeground);
-addSettingMapping('selection', colorRegistry.editorSelection);
+addSettingMapping('selection', colorRegistry.editorSelectionBackground);
 addSettingMapping('inactiveSelection', colorRegistry.editorInactiveSelection);
 addSettingMapping('selectionHighlightColor', colorRegistry.editorSelectionHighlight);
 addSettingMapping('findMatchHighlight', colorRegistry.editorFindMatchHighlight);