JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.12.4/jquery.min.js"></script>
	<title></title>
<body>


<table border="1px">
	<tr>
		<td><span>1</span></td>
		<td><span>2</span></td>
		<td><span>3</span></td>
		<td><span>4</span></td>
		<td><span>5</span></td>
		<td><span>6</span></td>
	</tr>
</table>

<button id="button">Start/Stop</button>
</body>

JavaScript

$("#button").click(function(){
	for (var i = $("span").length; i > 0; i--) {

		setTimeout(function(){
  			$("span:nth-child("+i+")").css("background-color","blue");
		}, 2000);
		
	}
});