You'll know the difference

frontend/src/components/Header.js

@@ -2,7 +2,7 @@ import React from "react";
 
 const Header = () => {
   return (
-    <header className="bg-blue-600 text-white p-4">
+    <header className="bg-black text-white p-4">
       <h1 className="text-xl font-bold">DownLink</h1>
     </header>
   );