src/vs/workbench/browser/parts/titlebar/titlebarPart.ts/TitlebarPart/updateStyles
class TitlebarPart:	override updateStyles(): void {
		super.updateStyles();

		// Part container
		if (this.element) {
			if (this.isInactive) {
				this.element.classList.add('inactive');
			} else {
				this.element.classList.remove('inactive');
			}

			const titleBackground = this.getColor(this.isInactive ? TITLE_BAR_INACTIVE_BACKGROUND : TITLE_BAR_ACTIVE_BACKGROUND, (color, theme) => {
				// LCD Rendering Support: the title bar part is a defining its own GPU layer.
				// To benefit from LCD font rendering, we must ensure that we always set an
				// opaque background color. As such, we compute an opaque color given we know
				// the background color is the workbench background.
				return color.isOpaque() ? color : color.makeOpaque(WORKBENCH_BACKGROUND(theme));
			}) || '';
			this.element.style.backgroundColor = titleBackground;

			if (this.appIconBadge) {
				this.appIconBadge.style.backgroundColor = titleBackground;
			}

			if (titleBackground && Color.fromHex(titleBackground).isLighter()) {
				this.element.classList.add('light');
			} else {
				this.element.classList.remove('light');
			}

			const titleForeground = this.getColor(this.isInactive ? TITLE_BAR_INACTIVE_FOREGROUND : TITLE_BAR_ACTIVE_FOREGROUND);
			this.element.style.color = titleForeground || '';

			const titleBorder = this.getColor(TITLE_BAR_BORDER);
			this.element.style.borderBottom = titleBorder ? `1px solid ${titleBorder}` : '';
		}
	}