Background color changer.

Background change on click.

<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8">
    <title></title>
    <link rel="stylesheet" href="style.css">
    <style type="text/css">
      body{
  margin: 0;
  padding: 0;
  background: #34495e;
}
.box{
  position: absolute;
  top: 40px;
  right: 40px;
  padding: 5px;
  background: #f1f1f1;
}
.box a{
  width: 40px;
  height: 40px;
  float: left;
  text-indent: -9999px;
  margin: 5px;
  cursor: pointer;
}
#red{
  background: #e74c3c;
}
#blue{
  background: #3498db;
}
#green{
  background: #2ecc71;
}
#gray{
  background: #34495e;
}
#yellow{
  background: #f1c40f;
}
#orange{
  background: #e67e22;
}

    </style>
  </head>
  <body>
<div class="box">
  <a onclick="changecolor('red')" id="red">#e74c3c</a>
  <a onclick="changecolor('blue')" id="blue">#3498db</a>
  <a onclick="changecolor('green')" id="green">#2ecc71</a>
  <a onclick="changecolor('gray')" id="gray">#34495e</a>
  <a onclick="changecolor('yellow')" id="yellow">#f1c40f</a>
  <a onclick="changecolor('orange')" id="orange">#e67e22</a>
</div>

<script type="text/javascript">
  function changecolor(id) {
    document.body.style.background = document.getElementById(id).innerHTML;
  }
</script>
  </body>
</html>