Been doing some testing this week with Debian Wheezy and noticed that Gnome's menu bar is black background with white font.

Had done a full gnome install and a minimal install.

Test machine is a Dell Optiplex GX270 and Gnome comes up in fall back mode because of the on board video(which is OK).

In settings the shell "theme" is grayed out with a !.

Would like to set it back to the white background on black fonts like Squeeze.

Any thoughts on this?

Wheezy is using Gnome 3.4 in testing and Sid. I think I read something about this being fixed in 3.6.

That is the default panel look for gnome3, black panel and white letters. Stable uses gnome2, so it is a totally different thing. But you can theme it anyway

I think Gnome 3 in fall back mode is not quite themeable (or at least, not all themes for Gnome 3 work as expected in fall back mode, in my experience), but you could download some themes from gnome-look.org and test them until you get the look you like.

In case this helps, the closest I got to a look like the one you describe (black fonts on white panels), was the Adwaita Cupertino theme (you can see it in the attached image). There are many others that may suit your tastes better.

About the Shell theme option, it's grayed out because the shell doesn't work in fall back mode.

Cheers.