Looks like a simple gamma filter, though that often does make a lot of games look much better, Just Cause 2 for example.
You can though obtain the same effect (with way less resources spent) using something as simple as f.lux for a lot of games: http://justgetflux.com/
f.lux is a great little program, helps a lot with reading at evening hours etc by regulating the light on your screen.
default settings were too colorful and shiny , i don't like to play world of warcraft
there were added bloom + hdr + vignette if i'm not wrong but you can edit the txt file as you wish , just open crpg , open the txt file , edit , , save , alt-tab and see the instant result.