Get your own website Result Size: 625 x 565
x
 
<!DOCTYPE html>
<html>
<head>
<style> 
#myDIV {
  width: 300px;
  height: 200px;
  border: 15px solid coral;
  animation: mymove 5s infinite;
}
@keyframes mymove {
  50% {border-left-color: lightblue;}
}
</style>
</head>
<body>
<h1>Animation of border-left-color</h1>
<p>Gradually change the border-left-color property from coral to lightblue, then back:<p>
<div id="myDIV"></div>
</body>
<!-- Mirrored from www.w3schools.com/cssref/tryit.php?filename=trycss_anim_border-left-color by HTTrack Website Copier/3.x [XR&CO'2014], Wed, 21 Dec 2022 16:50:29 GMT -->
</html>