This requires a Pixel Shader 3 GFX chip.
(ATI users can use RadionPro)
SweetFX is a shader bundle created by ceejay.dk with collaboration from other community users from Guru3D and other internet forums. SweetFX packs some post-processing shaders like LumaSharpen, Technicolor, Sepia and Vignette to name a few, giving the ability to change games colors and other effects beyond original game settings.
SweetFX has been integrated with RadeonPro to make easy its use by eliminating the need of copying SweetFX files into games directories.
Another advantage of using SweetFX through RadeonPro is the ability to use it in 64-bit games
http://www.radeonpro.info/features/post ... g/sweetfx/The goal of this software is to provide similar tools to games in realtime, as video processing software provides for movies and videos. You will need some technical grasp to be able to work with this software though.
http://www.guru3d.com/files_details/swe ... nload.html
OpenGL users can try QeffectsGL
The site has many "before and after" screen-shots of various games so you can see the defaults.