Keyframes loop in css

.obj{
  width: 80px;
  height: 80px;
  background-color: red;
  margin: 8px;
  -webkit-animation: anim 5s infinite;
  -moz-animation: anim 5s infinite;
  -o-animation: anim 5s infinite;
  animation: anim 5s infinite;
}
@keyframes anim {
  0% {background-color: red;}
  10% {background-color: orange;}
  20% {background-color: yellow;}
  40% {background-color: green;}
  60% {background-color: blue;}
  80% {background-color: indigo;}
  100% {background-color: purple;}
}