CSS Colors don't show up correctly on some computers. [**resolved**]

[WALDO]

I got an e-mail on Sunday about one of my sites Stating that the black text on the dark blue background made it really difficult to read.

I'll bet. I couldn't even fathom reading black text on a dark blue background, much less actually using that on a website. None of the websites I've ever built have had that. I started thinking this woman was a crackpot. In particular because this was the website she was referring to:

AudubonSymphony.org

From my perspective, the background was yellow, like it should have been. I started showing it to some co-workers. I actually found a user who saw the blue background.

I was shocked. I thought to myself how did you do that? Then he told me he was using a MAC. I asked him to look at it on his PC and see if he got the same result. He got the yellow background on his PC (both using IE5).

I'm guessing that this is a MAC issue, perhaps with CSS.Does anybody know why this might happen.

(before you answer, I already know that I didn't use a "safe" color. theoretically, those colors should dither, not change drastically, right?)