gummy

Set screen temperature to 3000K

$ gummy -t [3000]

$ gummy --backlight [50]

$ gummy -b [45]

$ gummy -b +10

$ gummy -b -10

$ gummy -s [1] -t [3800] -b [65]

gummy [options]

gummy is a screen brightness and color temperature manager for Linux systems running X11. It provides both software-based (gamma) adjustments and hardware backlight control.
The tool can adjust color temperature for reduced eye strain, particularly useful for night-time computing. Brightness can be controlled either through software gamma correction or hardware backlight where available.

-t, --temperature KELVIN

Set screen color temperature in Kelvin

Set pixel brightness (use +/- for relative changes)

Set hardware backlight level

Apply settings to specific screen (0-indexed)

Requires X11; does not work with Wayland. Hardware backlight control may require appropriate permissions or udev rules. Software brightness affects gamma, not actual backlight intensity.

gummy was developed as a simple, command-line alternative to graphical redshift applications for managing screen brightness and temperature on Linux.

redshift(1), xrandr(1), brightnessctl(1)