JSFiddle - React, Tailwind, and code Playground

HTML

<ul>
    <li>Test</li>
</ul>

CSS

li { background-color:#ff0000 }

JavaScript

var x = false;
setInterval(function() {
    $("li").css("background-color", x ? "#ff0000" : "#ffaa00");
    x = !x;
}, 500);