Repeating animation every 5m

HTML

<div>
</div>

CSS

div {
      width: 300px;
      height: 300px;
      animation: anim 10s infinite;
      background: brown;
    }
    
    @keyframes anim {
      0% {
        background: red;
      }
      50% {
        background: blue;
      }
      100% {
        background: blue;
      }
    }