Well that's because those free forum softwares are done in PHP. If you have access, and Im pretty sure you don't, to the css file of your forum, then it wouldn't be hard.
If I'm not mistaken, the new forum has a simple Design Customization-like section?
If you get your own domain, whether it be co.cc or whatever other free domain service is out there, I will create you an updated PhpBB forum or MyBB using my hosting and administrate the privileges of it to you and the other moderators on the Ucozers forum.
I even took time out to create this http://ucozers.thexcorez.com/, if you do not want it, then I will delete the database and subdomain. If you do, tell me now. MyBB or PhpBB. (personally MyBB has more customization features than PhpBB, in my opinion).
It's a take it or leave it, kindly.