<smil xmlns="http://www.w3.org/2005/SMIL21/Language">
  <head>
    <layout>
      <root-layout backgroundColor="white" width="640" height="480"/>
      <region height="100" width="100" id="timedElement" backgroundColor="#00ff00" />
      <region id="r" fit="fill"/>
    </layout>
  </head>
  <body>
    <par dur="indefinite">
      <animateColor id="a1" targetElement="timedElement" attributeName="backgroundColor" begin="1" dur="2s" additive="sum" to="#0000ff" fill="remove" calcMode="paced"/>
      <text region="r" left="0%" top="80%" width="100%" height="20%" dur="20s" fit="hidden"
            src="data:,animateColor%20id=%22a1%22%20targetElement=%22timedElement%22%20attributeName=%22backgroundColor%22%20begin=%221%22%20dur=%222s%22%20additive=%22sum%22%20to=%22%230000ff%22%20fill=%22remove%22%20calcMode=%22paced%22"/>
    </par>
  </body>
</smil>