JSFiddle - React, Tailwind, and code Playground

HTML

<style>
  <div> {
    width: 100%;
    height: 400px; 
    background-color: orange;
    margin: 0 auto 40px auto;
    border: 4px solid green;
     /*border-radius: 8px; */
    box-shadow: 3px 3px 2px gray;
    box-sizing: border-box;
    padding-top: 20px;
    animation-delay: 2s;
  }
  
  
  h1 {
    border: 2 px solid green;
    border-radius: 6px;
    box-shadow: 4px 4px 3px gray;
    font-size: 2.5em;
    text-align: center;
    color: blue;
    background: lightblue;
  }
  
  .d1, .d2,.d3 {
    border-radius: 8px;
    animation-name: couleur; 
    animation-duration: 6s;
    animation-iteration-count: infinite;
    font-family: serif;
    font-size: 5em;
    text-align: center;
    color: orange;
    margin-bottom: 6px;
  }
  
  @keyframes couleur {
    from{background-color: orange;}
    50% {background-color: green;}
    to {background-color: orange;}
    }
    
    footer {
      font-size: 1.5em;
      color: blue;
    }
            
</style>  

<h1>Animation couleur HTML et CSS</h1>
<div class="d1">WAAOOUUH !</div>
<div class="d2">THE FRENCH RAFALE</div>
<div class="d3">IS FANTASTIC PLANE !!</div>
<footer>Harmo</footer>