- preg_replace: documentation ( source)
<?php
// your code goes here
$html = '<body link="#0066FF" vlink="#6633CC" bgcolor="#4CDCFF" style=\'margin:0\'>';
echo preg_replace('#<body link="\#[a-zA-Z0-9]+" vlink="\#[a-zA-Z0-9]+" bgcolor="\#[a-zA-Z0-9]+" style=\'margin:0\'>#', $head, $html);