<svg xmlns="http://www.w3.org/2000/svg" width="100" height="100">
  <rect width="100" height="100" class="s0"/>
  <style>
  @keyframes pop { from { fill: red; } to { fill: green; } }
  @-webkit-keyframes pop { from { fill: red; } to { fill: green; } }

  .s0 {
      animation-name: pop;
      animation-duration: 0.001s;
      animation-iteration-count: 1;
      animation-fill-mode: forwards;
      -webkit-animation-name: pop;
      -webkit-animation-duration: 0.001s;
      -webkit-animation-iteration-count: 1;
      -webkit-animation-fill-mode: forwards;
  }
  </style>
</svg>