Working on that too. This is what Shawn Nash of iRacing said:
"There is an issue with contrast and color balance. We're working on graphics updates that deal with that, and true HDR lighting, DOF blurr, etc. We've had higher priorities right now, but all of that stuff is on our todo list. I've been able to play around with the contrast and color balance and it makes a huge difference.
Our track surface shaders are very lame right now. :-) The only objects with shaders doing anything complicated are the cars.
Shawn Nash, iRacing Staff"
I'm looking forward to that update, you'd think just tweaking contrast and color couldn't take that long to get in there.