First of all, sorry for not noticing your post for a few weeks. The forums here have been so quiet I'd gotten out of the habit of checking for posts.
I'm not sure what you mean by the backgrounds of the buttons not matching the overall design. I tried to make the Tikipedia theme a pretty close implementation of the Mediawiki Vector theme currently used at wikipedia.org. Can you describe more specifically what buttons aren't styled to match the original Mediawiki theme?
I don't have a Mediawiki-powered site myself (and haven't edited any wikipedia pages in a long time) so may have missed some button styling detail, although I do see some buttons on http://en.wikipedia.org/w/index.php?title=Colona,_Illinois&action=edit that simply use the browser's default button styling. If you have a URL or a screenshot that shows another style, please post it. There are probably other theme details that could be improved; the forum looks a little unstyled now that I look at it again, for example, so I'll try to spend some more time on the theme.