JSFiddle - React, Tailwind, and code Playground

HTML

<div id="box"></div>

CSS

#box {
    width: 256px;
    height: 256px;
    background-color: #444;
}

JavaScript

$('#box').on('click', function() {
    var box$ = $(this),
        isBgColorChanged = box$.data('isBgColorChanged'),
        bgColor = !!isBgColorChanged ? '#444' : '#ccc';
    box$.css('background-color', bgColor)
        .data('isBgColorChanged', !isBgColorChanged);
});