Fix #58667

src/vs/workbench/browser/parts/activitybar/activitybarPart.ts

@@ -207,7 +207,7 @@ export class ActivitybarPart extends Part {
 			badgeBackground: theme.getColor(ACTIVITY_BAR_BADGE_BACKGROUND),
 			badgeForeground: theme.getColor(ACTIVITY_BAR_BADGE_FOREGROUND),
 			dragAndDropBackground: theme.getColor(ACTIVITY_BAR_DRAG_AND_DROP_BACKGROUND),
-			activeBorderBottomColor: null,
+			activeBackgroundColor: null, inactiveBackgroundColor: null, activeBorderBottomColor: null,
 		};
 	}
 

src/vs/workbench/browser/parts/compositeBarActions.ts

@@ -113,6 +113,8 @@ export class ActivityAction extends Action {
 }
 
 export interface ICompositeBarColors {
+	activeBackgroundColor: Color;
+	inactiveBackgroundColor: Color;
 	activeBorderBottomColor: Color;
 	activeForegroundColor: Color;
 	inactiveForegroundColor: Color;
@@ -158,7 +160,7 @@ export class ActivityActionItem extends BaseActionItem {
 
 		if (this.label) {
 			if (this.options.icon) {
-				const foreground = this._action.checked ? colors.activeForegroundColor : colors.inactiveForegroundColor;
+				const foreground = this._action.checked ? colors.activeBackgroundColor || colors.activeForegroundColor : colors.inactiveBackgroundColor || colors.inactiveForegroundColor;
 				this.label.style.backgroundColor = foreground ? foreground.toString() : null;
 			} else {
 				const foreground = this._action.checked ? colors.activeForegroundColor : colors.inactiveForegroundColor;

src/vs/workbench/browser/parts/panel/panelPart.ts

@@ -95,6 +95,8 @@ export class PanelPart extends CompositePart<Panel> implements IPanelService {
 			compositeSize: 0,
 			overflowActionSize: 44,
 			colors: theme => ({
+				activeBackgroundColor: theme.getColor(PANEL_BACKGROUND), // Background color for overflow action
+				inactiveBackgroundColor: theme.getColor(PANEL_BACKGROUND), // Background color for overflow action
 				activeBorderBottomColor: theme.getColor(PANEL_ACTIVE_TITLE_BORDER),
 				activeForegroundColor: theme.getColor(PANEL_ACTIVE_TITLE_FOREGROUND),
 				inactiveForegroundColor: theme.getColor(PANEL_INACTIVE_TITLE_FOREGROUND),