xgamma
Adjust X11 display gamma correction
TLDR
SYNOPSIS
xgamma [options]
DESCRIPTION
xgamma queries and alters the gamma correction of a monitor via the XFree86-VidModeExtension. Gamma affects mid-tone brightness; values below 1.0 increase contrast while values above 1.0 decrease it.When invoked without gamma arguments, xgamma prints the current red, green, and blue gamma values to standard output. Gamma values are transmitted to the X server with three decimal places of precision. 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. The DISPLAY environment variable provides the default host and display number.
PARAMETERS
-gamma value
Set gamma for all color channels.-rgamma value
Set red channel gamma.-ggamma value
Set green channel gamma.-bgamma value
Set blue channel gamma.-display name
X display to use.-screen num
Screen number to adjust.-quiet
Suppress normal output.-help
Show usage summary and exit.
CAVEATS
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.
HISTORY
xgamma is part of the X.Org utility collection and was originally authored by Kaleb Keithley and David Dawes. It relies on the XFree86-VidModeExtension, which is considered obsolete; modern setups should prefer xrandr with the RandR 1.2+ gamma properties.
