JSFiddle - React, Tailwind, and code Playground

HTML

<div class="box"> </div>

CSS

@keyframes colorbox {
  0% {
    background:red;
  }
  40% {
    background: green;
  }
  80% {
    background: blue;
  }
  100% {
    background: red;
  }
}

.box {
   width:200px;
   height:200px;
   animation: colorbox 5s infinite ease-in-out;
}