Class "clear", pros/cons?

Try this:

Keep refreshing the page and see how the colours change:

http://johns-jokes.com/downloads/sp-a/php-in-css/

Please note the site is cached. When viewing the source the additional code is due to Cloud Hosting. I would be very grateful if anyone knows how to disable this feature only on this page and not on the complete site.

file: style-001.php



<?php header("Content-type: text/css;charset:UTF-8");
  $hex = mt_rand(0,17);
  $x   = sprintf('%x', $hex);
  $bg0 = $x.$x.$x;
  $bg1 = 'f' .$x .'f';
  $bg2 =  $x .'ff';
  $bg3 = 'ff' .$x;

?>
body {background-color:#<?php echo $bg0;?> }

h1  {background-color:#<?php echo $bg1;?> }
h2  {background-color:#<?php echo $bg2;?> }
h3  {background-color:#<?php echo $bg3;?> }

div {width:88%; margin:1em auto; background-color:#eff; color:#000}


file: index.php



<?php /* */ ?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
  "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" lang="en" xml:lang="en">
<head>
  <title>Just Playing with PHP and CSS</title>
  <link type="text/css" href="style-001.php" rel="stylesheet" />
</head>
<body>

  <h1>Heading 1</h1>
  <h2>Heading 2</h2>
  <h3>Heading 3</h3>
  <div>
    <a href='http://www.sitepoint.com/forums/showthread.php?870800-Class-quot-clear-quot-pros-cons'>
      Sitepoint discussion
    </a>
    <br /><br />
    <?php highlight_file('style-001.php');?>
  </div>
</body>
</html>