cache hex-to-rgba outputs

lib/styles/utils/hex-to-rgba.ts

@@ -0,0 +1,9 @@
+import hexToRgba from "hex-to-rgba";
+import mem from "mem";
+
+// removes spaces from default hex-to-rgba output and caches the result
+const memoized = mem((color: string, alpha?: number) => hexToRgba(color, alpha).replace(/\s/g, ""), {
+  cacheKey: (arguments_) => arguments_.join(","), // https://github.com/sindresorhus/mem#caching-strategy
+});
+
+export default memoized;