I just installed the recently released Mac OS 10.4. Thankfully Lux appears to work without any problems. One thing that I immediately noticed was that all the text that gets drawn on the board looks different. I investigated further and have come to the conclusion that when OSX 10.4 anti-aliases text it uses colors, even if the text is black on a white background!
This isn't just for Lux though, the system does it everywhere. Here's are close-ups of the OSX menubar that show the difference between the 10.3 and 10.4 (close-ups provided by the lovely developer tools app Pixie):