I’ve been working on a project using Visual Studio Tools for Office 2008 (VSTO) and at one point I needed to get the colors for categories in Outlook 2007. There are actually 3 colors, and they are returned as uint’s–why the .Net wrappers don’t convert to colors for you, I don’t know (to avoid linking to System.Drawing?).
The important thing is to convert them into the friendly System.Drawing.Color objects I know and love. For this task, there exists a handy ColorTranslator class. There is a FromOle method that does the exact chore you need. Here’s a sample of my code: