JSFiddle - React, Tailwind, and code Playground

HTML

<div id="sys53" class="cell">53
            </div>

CSS

.cell{
            display: table-cell;
            border-style: solid;
            border-width:15px;
            padding-left: 30px;
            padding-right: 30px;
            padding-top: 30px;
            padding-bottom: 30px;
            font-weight:5000;
            font-size:200%;
            background: #00FF00;


        }

JavaScript

$(".cell").click(function(){
           var clr = $( this ).css("background-color").toString(); 
           var clr = (clr == "rgb(255, 0, 0)" ? "rgb(255,0,0)" : "rgb(0, 255, 0)");
           $(this).css({
            "background":""+clr+""
            });

});