JSFiddle - React, Tailwind, and code Playground

HTML

<ul>
    <li data-background="#FF5555">
        <input "type=checkbox" name="color[]" value="Brick_Red">
        <span>Brick Red</span>
    </li>
</ul>

CSS

.colorBox {
    background-color: #FF1111;
}

JavaScript

$("li span").prepend('<div class="colorBox"></div>').css('background-color', $(this).parent().attr("data-background"));   
});