src/vs/workbench/services/themes/browser/workbenchThemeService.ts/WorkbenchThemeService/restoreColorTheme
class WorkbenchThemeService:	public async restoreColorTheme(): Promise<boolean> {
		const settingId = this.settings.colorTheme;
		const theme = this.colorThemeRegistry.findThemeBySettingsId(settingId);
		if (theme) {
			if (settingId !== this.currentColorTheme.settingsId) {
				await this.setColorTheme(theme.id, undefined);
			}
			return true;
		}
		return false;
	}