removeClass(class)の使い方

Red
Green
Blue

div.red { background-color:Red; }     
div.green { background-color:Green; }
div.blue { background-color: Blue; }

$("div:eq(0)").removeClass("red");
$("div:eq(1)").removeClass("green");
$("div:eq(2)").removeClass("blue"); 
        
<div class="red">Red</div>
<div class="green">Green</div>  
<div class="blue">Blue</div>