I’ve noticed that very, very, very few websites use purple as a color for anything, including text, illustrations, navigation, design elements, background colors, animation … just about anything. I find this incredibly fascinating (this, as the country is going to war, I know). I’m not sure of the exact reasons but here are my suppositions:
1. Purple doesn’t have a “cool” factor, unless your name happens to be Prince.
2. Purple doesn’t read very well; it’s not legible for most people, in part because it’s so unused.
3. Purple is fey, and perhaps its use is considered too feminine for the male-focused Web.
4. Purple has a coyness about it, and a cheapness, that recalls bordellos, or overly permissive sexuality.