0

xcalib commands follow this structure

xcalib -color <gamma> <brightness-percent> <contrast-percent>

I then issue two commands as one to try and adjust the amount of red on my screen. This does make the screen 'red'er.

xcalib -green 0.1 0 1 -alter && xcalib -blue 0.1 0 1 -alter

Why then don't the three sets of commands shown below produce different results? Notice I vary the gamma argument each time, eg 0.1, 0.9, 50. Yet my screen is heavy red under each command.

xcalib -green 0.1 0 1 -alter && xcalib -blue 0.1 0 1 -alter
xcalib -green 0.9 0 1 -alter && xcalib -blue 0.9 0 1 -alter
xcalib -green 50 0 1 -alter && xcalib -blue 50 0 1 -alter

What would be some xcalib commands to vary the amount of red, rather than have a hard on/off, which my commands above yield.

Note - I am aware that I could use GNOME night light, which is buggy on my installation. Or I could use redlight, which also has issues. But I prefer xcalib for it's simplicity, and I like manually setting things vs flux, redlight, etc changing settings as the sun rises and sets.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Browse other questions tagged or ask your own question.