To extend your vision on foggy maps try this...
It's a place to start they say...
.7 Brightness
.9 Gamma
.6 Contrast
I have my monitor set to the blue preset.
Play with it...it's worth it. It worked for me. You have to realize that you video card and monitor will pay a significant roll in what you are able to adjust. Some monitors have presents (red, blue, green - sometime called warm or cool) and manual adjustments. Like monitors, video card have the ability to adjust certain settings; color being one of them. You can edit all channels together (RBG) or individually. Be advise - there are specific settings in the video control panel that will adjust fog settings (I don't recall what they are, but I've read about them) - tinker at you own risk as it may result in a kick.
I am using a nVidia GeForce 8600 GTS driving two Dell 19" Flat Panel monitors.