JSFiddle - React, Tailwind, and code Playground

HTML

<div class="background">
    <div class='masked'>
    </div>
</div>

CSS

.background {
    background: -webkit-gradient(linear, left top, right bottom, color-stop(0%,#959595), color-stop(46%,#0d0d0d), color-stop(50%,#010101), color-stop(53%,#0a0a0a), color-stop(76%,#4e4e4e), color-stop(87%,#383838), color-stop(100%,#1b1b1b));
    width: 250px;
    height: 250px;
    float:left;
}
.masked {
    width: 200px;
    margin: 25px;
    height: 200px;
    background-color: #37b;
    -noobed-mask-image: url(http://stackoverflowimages.excitedstatelaboratory.com/mask-example-image-2.png);
}