src/vs/platform/theme/common/colorRegistry.ts/ColorRegistry/resolveDefaultColor
class ColorRegistry:	public resolveDefaultColor(id: ColorIdentifier, theme: IColorTheme): Color | undefined {
		const colorDesc = this.colorsById[id];
		if (colorDesc && colorDesc.defaults) {
			const colorValue = colorDesc.defaults[theme.type];
			return resolveColorValue(colorValue, theme);
		}
		return undefined;
	}