<!DOCTYPE html>
<html>
 <head>
  <title>Gradient interpolation</title>
  <link rel="author" title="Mike Bremford" href="mailto:mike@bfo.com">
  <style>
   .test {
       width: 100px;
       height: 100px;
       background: red;
       background: lch(60% 60 0);
   }
 </style>
 </head>
 <body>
  <div class="test"></div>
 </body>
</html>