src/vs/workbench/services/themes/common/colorThemeData.ts/TokenColorIndex/get
class TokenColorIndex:	public get(color: string | Color | undefined): number {
		color = normalizeColor(color);
		if (color === undefined) {
			return 0;
		}
		let value = this._color2id[color];
		if (value) {
			return value;
		}
		console.log(`Color ${color} not in index.`);
		return 0;
	}