r_ignorehwgamma

r_ignorehwgamma ignore or allow the gamma and brightness settings.

Usage:
/seta r_ignorehwgamma 0
then do:
/vid_restart

Values: 0 (enabled) /  1 (not enabled)

Note:
1 by default in RTCW and 0 by default in ET.
Requires vid_restart to take effect.
When enabled ( 0 ) external gamma correction will not be used at the video driver level.