Parameters: grab 'color' URL param to override starting iconColor

src/components/App/App.tsx

@@ -1,6 +1,7 @@
 import React, { Suspense } from "react";
 
 import "./App.css";
+import Parameters from "../Parameters/Parameters";
 import Header from "../Header/Header";
 import Toolbar from "../Toolbar/Toolbar";
 import IconGrid from "../IconGrid/IconGrid";
@@ -15,6 +16,7 @@ const waitingFallback = <Notice type="none" message="" />;
 const App: React.FC<any> = () => {
   return (
     <React.StrictMode>
+      <Parameters />
       <Header />
       <main>
         <Toolbar />

src/components/Parameters/Parameters.tsx

@@ -0,0 +1,22 @@
+import React, { useEffect } from "react";
+import { useSearchParam } from "react-use";
+import { useSetRecoilState } from "recoil";
+import TinyColor from "tinycolor2";
+
+import { iconColorAtom } from "../../state/atoms";
+
+const Parameters: React.FC<{}> = () => {
+  const color = useSearchParam("color")?.replace(/["']/g, "");
+  const setColor = useSetRecoilState(iconColorAtom);
+
+  useEffect(() => {
+    if (color) {
+      const normalizedColor = TinyColor(color);
+      if (normalizedColor.isValid()) setColor(normalizedColor.toHexString());
+    }
+  }, [color, setColor]);
+
+  return null;
+};
+
+export default Parameters;