Xcalib

To load a colour profile, just invoke xcalib along with the path to your colour profile:

$ xcalib /usr/share/color/icc/eciRGB_v2_profile-2011/eciRGB_v2_ICCv4.icc

Ideally, you will have created a colour profile for your monitor with a colour calibrator like Color Hug, or else managing colour profiles of your screen is probably not doing much good.

If you use multiple screens, us the -s flag. By default, -s is set to 0 to represent the primary screen. If you have two screens, for example, you may choose between -s 0 and -s 1.

$ xcalib -s 1 /usr/share/color/icc/eciRGB_v2_profile-2011/eciRGB_v2_ICCv4.icc

There's a small chance that you might set your display as one big screen. If this is how you manage your display, then both physical monitors are treated as one “screen”, so xcalib would impose the same profile to both. To change that behaviour, change your display settings in KDE System Settings.

To have this happen automatically upon boot, add that command to your ~/.bash_profile file.

Make fine adjustments to the current colour profile of your display with a trailing -a or -alter flag. For instance, to boost the blue levels of your current profile:

$ xcalib -blue 1.0 10.0 100.0 -a

Which takes the blue at gamma level 1.0 (1 through 5 are valid), and sets its brightness to 10% and its contrast to 100%.

To lower the blue in the current profile:

$ xcalib -blue 1.0 10.0 60.0 -a

Which takes the blue levels at 1.0 gamme and sets its brightness to 10% but its contrast to 60%.

These settings can be done to -red, -green, or -blue.

Calibration alterations can be re-set with -c or -clear:

$ xcalib -c

To automate xcalib, add an xcalib command to your ~/.bash_profile file.