CVar colorblindsimulator

colorblindshader changes the colors in the game engine for various color blind issues.

Default Setting

0: Disabled. Normal color vision.; http://i.imgur.com/r02cV.jpg
1: Protanopia (1% of males). The inability to see red.; http://i.imgur.com/neeIo.jpg
2: Protanomaly (1% of males, 0.01% of females). Decreased sensitivity to red.; http://i.imgur.com/MuS8P.jpg.
3: Deuteranopia (1% of males). The inability to see green.; http://i.imgur.com/xW8xz.jpg
4: Deuteranomaly (6% of males, 0.4% of females). Decreased sensitivity to green.; http://i.imgur.com/zXJIW.jpg.
5: Tritanopia (rare). The inability to see blue.; http://i.imgur.com/DoHKf.jpg
6: Tritanomaly (rare). Decreased sensitivity to blue.; http://i.imgur.com/Un83x.jpg
7: Achromatopsia (very rare). Full colorblindness. Inability to see any color. The person sees a black/white world. They have other sight issues like being very sensitive to light (photophobia) and having a decreased sharpness in their vision which cannot be adjusted by wearing glasses. The additional conditions (less sharp vision and photophobia) are not simulated with this setting.; http://i.imgur.com/dnI4f.jpg
8: Achromatomaly (very rare). Decreased sensitivity to all colors.; http://i.imgur.com/y1gwV.jpg

In-game, type the following

/console colorblindshader setting

Alternatively, you can exit wow, open the Config-cache.wtf file, and add the following line:

SET colorblindshader "setting"

Patch 4.3.0 (2011-11-29): Added