JSFiddle - React, Tailwind, and code Playground

HTML

<div id="color" class='red'></div>

CSS

#color{
    background-color:red;
}
.red{
    background-color:red;
}

JavaScript

alert($('#color').css('background-color'));
if($('#color').css('background-color')=='red'){
    alert('first if');
}
if($('#color').hasClass('red')){
    alert('second if');
}