JSFiddle - React, Tailwind, and code Playground

HTML

<link rel="stylesheet" href="http://netdna.bootstrapcdn.com/font-awesome/3.2.1/css/font-awesome.min.css">
<i class="icon-star red-border"></i>

CSS

.icon-star.red-border {
    position: relative;
    color: blue;
    font-size: 24px;
}

.icon-star.red-border:after {
    content: "\f006";
    color: red;
    position: absolute;
    left: 0;    
}