src/vs/workbench/contrib/debug/browser/exceptionWidget.ts/ExceptionWidget/applyTheme
class ExceptionWidget:	private applyTheme(theme: IColorTheme): void {
		this.backgroundColor = theme.getColor(debugExceptionWidgetBackground);
		const frameColor = theme.getColor(debugExceptionWidgetBorder);
		this.style({
			arrowColor: frameColor,
			frameColor: frameColor
		}); // style() will trigger _applyStyles
	}