I love it tomyeah, thanks... have implemented it on my site, http://www.mondaymorningphoto.com
One thing though - I had to change a couple of the paths... in case anyone else gets a lot of errors popping up when they log in to their admin page (I'm using PP 1.5)... I changed lines 241 and 242 of the admin_harmonious.php from:
$image_path = "images/".$image_name;
$cached_string = "cache/" . md5($image_name);
$image_path = "../images/".$image_name;
$cached_string = "../cache/" . md5($image_name);
...which got everything working (well, no errors when I log in to the admin part of the site... the colours were working fine before that anyway!)
Thanks again for a cool addon!