JSFiddle - React, Tailwind, and code Playground

HTML

<body id="demo">
    <button type="button" onclick="chC();">change</button>
</body>

JavaScript

function chC() {
    var cl = document.getElementById('demo');
    var colNo = Math.ceil(Math.random() * 4);
    
    switch (colNo) {
        case 1:
            cl.style.background = 'red';
            break;
        case 2:
            cl.style.background = 'yellow';
            break;
        case 3:
            cl.style.background = 'pink';
            break;
        default:
            cl.style.background = 'orange';
    }

}