Don't mind if I ask, but... is that purple tint supposed to be there? If it shows up in the screenshots and not just on your monitor, something tells me that the gamemakers might have intended for it to look that way; perhaps you can do a quick check on their forums.
If the screenshots match screenshots from game reviews, then that's even more reason to believe that there's nothing wrong. I'm not sure if video card adjustments to the video output are applied to the video stream from which screenshots are taken; if they are applied to the screenshots as well, you could play around with video driver settings and see if it helps any.