src/vs/workbench/services/themes/common/colorThemeData.ts/ColorThemeData/toStorage
class ColorThemeData:	toStorage(storageService: IStorageService) {
		let colorMapData: { [key: string]: string } = {};
		for (let key in this.colorMap) {
			colorMapData[key] = Color.Format.CSS.formatHexA(this.colorMap[key], true);
		}
		// no need to persist custom colors, they will be taken from the settings
		const value = JSON.stringify({
			id: this.id,
			label: this.label,
			settingsId: this.settingsId,
			themeTokenColors: this.themeTokenColors.map(tc => ({ settings: tc.settings, scope: tc.scope })), // don't persist names
			semanticTokenRules: this.semanticTokenRules.map(SemanticTokenRule.toJSONObject),
			extensionData: ExtensionData.toJSONObject(this.extensionData),
			themeSemanticHighlighting: this.themeSemanticHighlighting,
			colorMap: colorMapData,
			watch: this.watch
		});

		// roam persisted color theme colors. Don't enable for icons as they contain references to fonts and images.
		storageService.store(ColorThemeData.STORAGE_KEY, value, StorageScope.GLOBAL, StorageTarget.USER);
	}