JSFiddle - React, Tailwind, and code Playground

HTML

<header id="header">
    <div>
    </div>
 </header>

CSS

header {
 background-color: #0683c9;
 width:600px;
 height: 1200px;
}

JavaScript

window.onscroll = function (e) {  
  document.getElementById("header").style.backgroundColor = "red";
}