Color Visibility

We've been looking at the problem of trying to determine what colors are good/bad for web page visibility. As part of the process, we wanted to set up a web site where people could go and 'vote' on several different color combinations. In this way we would get some real world results. Our example site is at:
http://aprompt.snow.utoronto.ca/ColorTest.html

Please take a look and let me know your comments.

I also have a small program the tries to determine whether colors are good/bad visibility for use in web pages. Let me know if you'd like to have a look at it.

Chris