JSFiddle - React, Tailwind, and code Playground

HTML

<div class="wrap">
    <div></div>
    <div></div>
    <div></div>
<div>

CSS

.wrap div{
    height:10px;
    width:10px;
    background-color : gray
}

JavaScript

window.c = 0;
window.count = $(".wrap div").length;
window.setInterval(function(){
    $('.wrap div').each(function(){
            $(this).css("background-color","gray")        
    })
        $('.wrap div:eq('+(window.c++)%window.count+')').css("background-color","red")
},1000)