Redshift is software that adjusts the computer display’s color temperature based upon the time of day. The program seeks to reduce eye strain as well as insomnia.
The software seeks to determine the user’s location during startup, and then goes into a loop setting the display gamma according to the time of day every couple seconds or minutes.
During twilight and early morning, the color temperature transitions smoothly from night to daytime temperature to allow your eyes to slowly adapt over a period of about an hour. At night the color temperature should be set to match the lamps in your room. This is typically a low temperature at around 3000K-4000K (default is 4500K). During the day, the color temperature should match the light from outside, typically around 5500K-6500K (default is 6500K). The light has a higher temperature on an overcast day.
Redshift interacts with the rest of the system in two ways: reading the location, and setting the gamma.
There are various frontends available for Redshift including redshift-gtk, redshift-plasmoid, and nightshift.
The software is released under an open source license.
Features include:
- Tray status icon that can enable or disable Redshift, or adjust the color temperature automatically.
- Set a single color temperature and brightness (“one shot mode”) or can adjust the temperature and brightness continuously to follow the sun’s elevation.
- Supports multiple monitors through the X extensions RandR (preferred) or VidMode, or through the Direct Rendering Manager.
- Uses GeoClue 2, a D-Bus service that provides location information.
- Support for custom transition start and end elevation.
- Allow separate brightness for day and night.
Website: jonls.dk/redshift
Support: GitHub code repository
Developer: Jon Lund Steffensen
License: GNU General Public License v3.0
Redshift is written in C. Learn C with our recommended free books and free tutorials.
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