I've written an article about web colour issues and a guide describing the best practice colour setup for web designers. My aim was to help clarify some of the Mac OS X vs Windows colour issues on the web and to provide details of a best practice setup.
A Guide to Cross Platform Web Colour
Best Practice Colour Setup for Web Designers
I have tried to keep the technical details to a minimum by only providing those needed to understand the practical issues. I hope readers find the article and the guide useful.