Towards a type safe color option

config/utils.js

@@ -3,6 +3,16 @@
 export const rainbow = "rgba(200,120,120,0.5);"
       + "--before-background: linear-gradient(40deg, #FF0000 0%, #00FF00 50%, #0000FF 70%, #FFFF00 100%);";
 
+export const hex = (hex: string) => hex;
+
+export const rgb = (r: number, g: number, b: number) => (
+  `rgb(${r.toString()}, ${g.toString()}, ${b.toString()})`
+);
+
+export const rgba = (r: number, g: number, b: number, a: number) => (
+  `rgb(${r.toString()}, ${g.toString()}, ${b.toString()}, ${a.toString()})`
+);
+
 export const esper_topics = (chip_id: string, name: string) => ({
   [ `esper_${name}_version` ]: {
     state: `/service/esper/${chip_id}/info`,