Code tested in Firefox browser as random.php

Code:
<?php

$r = rand(128,255);
$g = rand(128,255);
$b = rand(128,255);

$tablebg = dechex($r) . dechex($g) . dechex($b);

?>
<html>
 <head>
  <title> Refresh and see </title>
 </head>
 <body bgcolor='<?php echo "#"."$tablebg"; ?>'>

 This is my Home page with random background color. <br>
 Refresh and see.

 </body>
</html>
Light colors are selected using $r = rand();. If you change the $r = rand(128,255); to $r = rand(0,255); deep color will be set as background color, which will cause difficulty in reading the text in the web page.