[ajuc]

I use f.lux - it changes the screen color temperature through the day to make it easier to sleep.

If I sit late at night my desktop walpaper (which is a regular photo with a lot of blue sky) becomes basically all red if you look at rgb values. But I still perceive the sky in it as blue because other things are "more red" so it looks blue, and because I know sky is blue, and because I remember how it looked before and the change happened slowly.

All of these scream "relativism" to me, in fact the mapping to common moral fallacies is surprisingly direct :) When law changes around you you might not recognize when it got evil. Obeying the law is good because it's the law. When everything around is evil - small evil seems good.

As for language and law - these are arbitrary. "Yellow pages" can be any color, so can "blue screen of death". Green traffic lights are actually blue in some countries.