Dervie the color while registering

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

@@ -203,7 +203,7 @@ export class ActivitybarPart extends Part {
 	private getActivitybarItemColors(theme: ITheme): ICompositeBarColors {
 		return <ICompositeBarColors>{
 			activeForegroundColor: theme.getColor(ACTIVITY_BAR_FOREGROUND),
-			inactiveForegroundColor: theme.defines(ACTIVITY_BAR_INACTIVE_FOREGROUND) ? theme.getColor(ACTIVITY_BAR_INACTIVE_FOREGROUND) : theme.getColor(ACTIVITY_BAR_FOREGROUND).transparent(0.6),
+			inactiveForegroundColor: theme.getColor(ACTIVITY_BAR_INACTIVE_FOREGROUND),
 			badgeBackground: theme.getColor(ACTIVITY_BAR_BADGE_BACKGROUND),
 			badgeForeground: theme.getColor(ACTIVITY_BAR_BADGE_FOREGROUND),
 			dragAndDropBackground: theme.getColor(ACTIVITY_BAR_DRAG_AND_DROP_BACKGROUND),

src/vs/workbench/common/theme.ts

@@ -291,8 +291,8 @@ export const ACTIVITY_BAR_FOREGROUND = registerColor('activityBar.foreground', {
 }, nls.localize('activityBarForeground', "Activity bar item foreground color when it is active. The activity bar is showing on the far left or right and allows to switch between views of the side bar."));
 
 export const ACTIVITY_BAR_INACTIVE_FOREGROUND = registerColor('activityBar.inactiveForeground', {
-	dark: Color.white.transparent(0.6),
-	light: Color.white.transparent(0.6),
+	dark: transparent(ACTIVITY_BAR_FOREGROUND, 0.6),
+	light: transparent(ACTIVITY_BAR_FOREGROUND, 0.6),
 	hc: Color.white
 }, nls.localize('activityBarInActiveForeground', "Activity bar item foreground color when it is inactive. The activity bar is showing on the far left or right and allows to switch between views of the side bar."));