I think somewhere, something got installed but I have no idea what or how to fix it :(
Basically, my old MacBook Pro running 10.5 Leopard had a problem where on boot it would show everything on the screen in a very sort of crunched color space. Everything below 15% white would just be pure black, everything above 85% white would be pure white and all colors look to be a touch more saturated. It's garish.
To fix it, I found that I could boot into almost any fullscreen 3D game. When the game launches, the colors would still be off, but when I then quite the game and return the desktop everything is normal again. I've noticed Blizzard games work most reliably for this (World of Warcraft or Starcraft2).
This problem has followed me through the years. When I upgraded to an iMac I migrated everything over to it, and the issue now happens on the iMac too. I then got a new MacBook Pro for work and migrated my iMac over to that, and it has the problem too. I had thought that it was an OS bug, but upgrading to 10.6 Snow Leopard didn't fix it and neither did 10.7 Lion. Furthermore I can't find any reference on any forum or help site where anyone else has this problem.
If anyone has any idea what processes or settings or apps I should look at to figure out why this is happening I should would appreciate it! It looks sort of irresponsible when I open my laptop in the office to work and then boot up Starcraft 2 full screen...