Redshift is an application that adjusts the computer display's color temperature based upon the time of day.

The program is free software and is intended to reduce eye strain, as well as insomnia[3] (see Sleep § Circadian clock and Phase response curve § Light).

[3] On Linux and BSD operating systems, Redshift supports multiple monitors through the X extensions RandR (preferred) or VidMode, or through the Direct Rendering Manager.

In addition to a windowed interface, it provides a tray status icon that can enable or disable Redshift or adjust the screen's color temperature automatically.

A simple script can be made and called upon to set the color temperature manually via a shortcut or panel launcher: Since 14 Jun 2020, Redshift development has been abandoned.