<html xmlns="http://www.w3.org/1999/xhtml" style="outline-color: black;">
  <head>
    <style>
      html { color: black; outline-width: 10px; outline-style: solid; }
    </style>
  </head>
  <body>
    <html style="outline-color: green;">Test</html>
  </body>
</html>