I've tried several color calibration software (monica, gnome-color-calibrator, kgamma), but neither of them worked.
I couldn't install the last two because of problems at make/configure. In the case of gnome-color-calibrator I suspect that I would need to install several co-dependent packages to make it work, but after an hour of wasting my time with dependencies, I gave up. Kgamma just gave me a few pages of cryptic error messages so I will leave it alone.
Monica -- surprisingly -- didn't worked either, but since it is just a front-end for xgamma, I tried to use this program which is a part of the core system or so it seems.
It did exactly nothing with my colors.
Now it seems that I'm struck here.
Is it really so impossible to calibrate the colors on an LCD display? What I could have done wrong?