<div>
div {
  height: 50px;
  width: 50px;
  animation:demo1 5s;
   -webkit-animation:demo1 5s infinite; /* Chrome & Safari*/
}

@keyframes demo1 {
  from {background:#0000CC;}
  to {background:#FFFF00;}
}

@-webkit-keyframes demo1 /* Chrome & Safari*/
{
from {background:#0000CC;}
to {background:#FFFF00;}
}

External CSS

This Pen doesn't use any external CSS resources.

External JavaScript

This Pen doesn't use any external JavaScript resources.