body {
  background: #201;
}

.box {
  width: 50px;
  height: 50px;
  display: inline-block;
  background-color: #f06;
  line-height: 50px;
  text-align: center;
  font-size: 25px;
  font-family: sans-serif;
  color: white;
}

.blue {
  background: dodgerblue;
}