xgamma

Display current gamma values

$ xgamma

$ xgamma -gamma [1.2]

$ xgamma -rgamma [1.1] -ggamma [1.0] -bgamma [0.9]

$ xgamma -display [:0] -gamma [1.2]

$ xgamma -screen [0] -gamma [1.1]

xgamma [options]

xgamma queries and sets gamma correction values for X11 displays. Gamma affects mid-tone brightness; values below 1.0 increase contrast while values above 1.0 decrease it.
The tool adjusts the video lookup table (LUT) through the X server. Default gamma is 1.0. Separate control of red, green, and blue channels allows color temperature adjustment.
Settings are temporary and reset on X server restart. For persistence, add xgamma commands to ~/.xinitrc or ~/.xprofile, or configure in xorg.conf.

-gamma value

Set gamma for all color channels.

Set red channel gamma.

Set green channel gamma.

Set blue channel gamma.

X display to use.

Screen number to adjust.

Suppress normal output.

X11 only; no effect on Wayland. Settings don't persist across reboots without scripting. May conflict with color management tools like Redshift. Hardware support varies.

xgamma is part of the X.Org utility collection, providing simple gamma correction since early X11 implementations. While largely superseded by xrandr for display configuration, xgamma remains useful for quick gamma adjustments.

xrandr(1), redshift(1), xcalib(1), xbrightness(1)