gammastep

Start with automatic location

$ gammastep

$ gammastep -l [37.7749:-122.4194]

$ gammastep -t [6500:3500]

$ gammastep -O [3500]

$ gammastep -x

$ gammastep -m wayland

gammastep [options]

gammastep adjusts screen color temperature based on time of day to reduce eye strain and improve sleep. It makes screens warmer (redder) at night and cooler (bluer) during day.
Gammastep is a fork of Redshift with Wayland support. It's commonly used with tiling window managers and supports automatic location detection or manual coordinates.

-l lat:lon

Manual location (latitude:longitude).

Color temperature (day:night Kelvin).

Brightness (day:night, 0.1-1.0).

One-shot mode with temperature.

Reset and exit.

Adjustment method: randr, wayland, drm.

Reset before applying.

Verbose output.

Disable gradual transition.

~/.config/gammastep/config.ini

Configuration for color temperature, brightness, and location settings.

Requires compatible display server (X11/Wayland). Automatic location needs geoclue or manual coordinates. Some applications may display colors inaccurately. Night light features in DEs may conflict.

Gammastep was forked from Redshift by Maxime Coste to add Wayland support. Redshift was created by Jon Lund Steffensen in 2009 based on research about blue light's effects on circadian rhythms.

redshift(1), xrandr(1), wlsunset(1)