8 bit color

My OS is Windows Xp Home Edition SP2 and has the options of High Color and True Color. My option was to run at True Color 1024 by 768 with 32 bit color. The 256 Color option is unique to Office Pro 2003. Since I have installed Office Pro 2003, Outlook opens in 256 Colors with 8 bit color. This is frustrating. How do I change the default so that True Color 1024 by 768 with 32 bit color is retained when I open Outlook?

if you go under my computer - programs - microsoft office - blabla and find outlook.exe or whatever, try right clicking - compatiblility tab, and see if "run in 256 colors" is selected.