<style>
  body {
    background-color: #FFFFFF;
  }
  .blue {
    background-color: #000000;
  }
  .yellow {
    background-color: #000000;
  }
  div {
    display: inline-block;
    height: 100px;
    width: 100px;
  }
</style>
<div class="blue"></div>
<div class="yellow"></div>