src/vs/platform/theme/common/colorRegistry.ts/ColorRegistry/registerColor
class ColorRegistry:	public registerColor(id: string, defaults: ColorDefaults | null, description: string, needsTransparency = false, deprecationMessage?: string): ColorIdentifier {
		let colorContribution: ColorContribution = { id, description, defaults, needsTransparency, deprecationMessage };
		this.colorsById[id] = colorContribution;
		let propertySchema: IJSONSchema = { type: 'string', description, format: 'color-hex', defaultSnippets: [{ body: '${1:#ff0000}' }] };
		if (deprecationMessage) {
			propertySchema.deprecationMessage = deprecationMessage;
		}
		this.colorSchema.properties[id] = propertySchema;
		this.colorReferenceSchema.enum.push(id);
		this.colorReferenceSchema.enumDescriptions.push(description);

		this._onDidChangeSchema.fire();
		return id;
	}