JSFiddle - React, Tailwind, and code Playground

HTML

<div class="color uno select">a</div>
<div class="color dos">b</div>
<div class="color tres">c</div>

CSS

.select { float:left; width:400px; height:400px; background-color:#0F0; background-color:green !important;}
.uno, .dos, .tres { float:left; width:100px; height:100px; }
.uno { background-color:red;}
.dos { background-color:blue;}
.tres { background-color:orange;}

JavaScript

$(".color").on("click",function(){
    if(!$(this).hasClass("select")){
        $(".color").removeClass("select");
        $(this).addClass("select");
    }
});