JSFiddle - React, Tailwind, and code Playground

HTML

<div class="container">
<div class="yellow"></div>
<div class="red"></div>
<div class="green"></div>
<div class="blue"></div>
<div class="pink"></div>
<div class="orange"></div>
<div class="black"></div>
<div class="white"></div>
</div>

CSS

div.container div{
    width:50px;
    height:50px;
    border:2px solid #000000;
}

JavaScript

$("div.container div").each(function(){
    var color = $(this).attr("class");
    $(this).css({backgroundColor: color});
});