Have you tried using the Windows Basic theme and if you want to, change the desktop background to a solid color? I'll have to ask for some help for you if that is not satisfactory. Just let me know.
Yaron, a better suggestion would be to look at some of the tutorials and ask your question here. That's what they do in that sub forum. Customization - Windows 7 Help Forums
I hope someone there can help and I'm sure they will. Customization of themes is not my thing. But we have some very talented people here who can do a lot of things with themes.