chromium/third_party/blink/web_tests/external/wpt/css/css-cascade/initial-background-color.html

<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <title>
    CSS Cascading and Inheritance Test:
    Initial property and background-color
  </title>
  <meta name="assert" content="
    The initial keyword is supported on background-color.
  " />

  <link
    rel="author"
    title="François REMY"
    href="mailto:[email protected]"
  / >

  <link rel="help" href="https://www.w3.org/TR/css-cascade-3/#initial"/>

  <link
    rel="match"
    href="reference/all-green.html"
  />

  <style type="text/css">

      html, body { margin: 0px; padding: 0px; }

      html { background: green; overflow: hidden; }
      #outer { position: absolute; top: 0px; left: 0px; width: 100%; height: 100%; }
      #outer { background: red; background-color: initial; }

  </style>

</head>
<body>

  <div id="outer"></div>

</body>
</html>