workaround issue with background color on mac

src/vs/workbench/electron-main/window.ts

@@ -175,7 +175,7 @@ export class VSCodeWindow {
 			height: this.windowState.height,
 			x: this.windowState.x,
 			y: this.windowState.y,
-			backgroundColor: usesLightTheme ? '#FFFFFF' : '#1E1E1E',
+			backgroundColor: usesLightTheme ? '#FFFFFF' : platform.isMacintosh ? '#171717' : '#1E1E1E', // https://github.com/electron/electron/issues/5150
 			minWidth: VSCodeWindow.MIN_WIDTH,
 			minHeight: VSCodeWindow.MIN_HEIGHT,
 			show: showDirectly && this.currentWindowMode !== WindowMode.Maximized, // in case we are maximized, only show later after the call to maximize (see below)