@keyframes example {
  0% {
    background-color: red;
  }
  25% {
    background-color: yellow;
  }
  50% {
    background-color: blue;
  }
  75% {
    background-color: green;
  }
  100% {
    background-color: red;
  }
}

.animated-item {
  position: relative;
  animation-name: example;
  animation-duration: 4s;
  animation-iteration-count: infinite;
}