precisely. I was taught as a kid that your own rights end where other people's right starts and that you should not molest others or make them feel uncomfortable. Some colours can indeed be an offense. If you need sunglasses to avoid damage to your eyes when passing your neighbour's neon-yellow door, you can request that next time he paints his door he might perhaps consider a less exotic shade. In extreme cases you'd stand good chances at court if you'd sue him for causing you physical and emotional harm.
I think trekkiedane
's comparism with nudity is very apt. Some people like to look at it, others don't. It sure depends on both the displayed body and the watcher's personal attitude toward nudity. But almost all countries have laws that forbid nudity in public or at least restrict it to certain areas. Doubtlessly, that's not out of concern for nekkid people to catch a cold but rather in order to spare people the view. If they'd like to see someone naked they can do so any time, privately at home.
Much the same goes for tattoos in my opinion. They are something not everyone wants to see and that should therefore be looked at privately, but not be forced upon all the world. Besides, which medium could be more private than one's skin?