Untitled

dabblet.css

body {
    background-color: #fff;
    color: #333;
    font-family: sans-serif;
    font-size: 20px;    
}

.box {
    margin: 10px;
    width: 150px;
    height: 150px;
    color: #fff;
    text-shadow: 1px 1px 2px #333;    
    opacity: 0.9;
}

.red {
    background-color: red;
}

.green {
    background-color: green;
}

.blue {
    background-color: blue;
}

.yellow {
    background-color: yellow;
}

dabblet.html

<div class="box red">red</div>
<div class="box green">green</div>
<div class="box blue">blue</div>
<div class="box yellow">yellow</div>

settings.json

{"view":"split-vertical","fontsize":"100","seethrough":"","prefixfree":"1","page":"css"}