How to adjust contrast with xcalib
Solution 1:
This is a workaround that achieves the same goal:
xbacklight -set 77
redshift -t 6100:6100 -g 0.8:0.8:0.8
Solution 2:
I had a similar problem with xcalib only working for 1-2 seconds, and in my case the problem was that I was already running redshift, which repeatedly sets the color settings to what it wants.
After I stopped redshift, xcalib worked as intended.