<!DOCTYPE html>
<!--
 | Setting 2 different color values for the edges of a rounded corners border.
 |   https://www.w3.org/TR/css3-background/#the-border-color
 -->
<html>
<head>
  <style>
    div {
      border: 25px solid;
      border-color: #00FFFF #FF7F50;
      border-radius: 50%;
      height: 200px;
      width: 400px;
    }
  </style>
</head>
<body>
  <div></div>
</body>
</html>