JSFiddle - React, Tailwind, and code Playground
HTML
<div class="red"></div>
<div class="green"></div>
<div class="blue"></div>
<div class="apple"></div>
CSS
.highlight { background-color: yellow; }
JavaScript
$(function() {
$('div').each(function() {
$(this).html($(this).attr('class'));
}).filter('.red, .green, .blue').addClass('highlight');
});