Today, I decided to be brash and install a new theme onto my lovely GNOME-run Edgy Eft installation of Ubuntu.
I decided that to get away from the windows deal, to install the MacOSX theme, and see how that ran, and to be quite honest, it looks lovely.
I have one slight problem, but it bugs me greatly. Whenever I have a menu open, and roll my mouse over the top of a menu item, normally, the text would be highlighted, in a slightly different colour to that of the menu itself, but the highlight color that I now get seems to change to the colour of the menu, and also changes the text colour to that of the menu so it makes it impossible to read the text that I have rolled my mouse over. I can, however, still see the icon of the option.
I have tried finding an option to change this in the themes selection window (system, preferences, themes) but alas, there is no option, it seems. Menus and Toolbars offers no helps, nor does fonts.

Is there any way I can change the highlight colour and if so, where do I find it?

You might want to check out this tutorial.

Thank you.
I shall start reading!

Do System-> Preferences-> Theme. Click the theme you're using and then click the Customize button. In the Colors tab you can adjust background and text colors to your preferences. I always save the customized theme I've created so that if I experiment with other themes and icons I can easily restore the theme to my favorite.

I think that feature is only available in Gnome 2.18, and I would assume that he is using 2.16.

Thanks for the tip, fragos, but I am afriad, cgjones is right. I haven't (to my knowledge, anyway!) updated the GNOME install on the machine from the original installation, so I would assume that GNOME 2.16 is (still) installed.
I think in my next venture, I shall update said window manager to 2.18.

Just to clarify, Gnome is a desktop environment, Metacity is a window manager.

Ubuntu 7.04 is scheduled for final release on the 19th and it includes Gnome 2.18.1 as well as a lot of other good things. I've been using it since the beta. IMHO, that is the path I'd recommend to get Gnome 2.18.

My bad, sorry

Funny, that, I was just thinking about this, and was wondering if it was worth just re-installing (wipe and install) or upgrading (via apt-get)....

Ubuntu recommends using the Update Manager for updates. That's what I've done in the past and the upgrades were trouble free. There are a lot of new features relating to installations so this time around I did a fresh install from a beta ISO I downloaded. It's working very well for me.