I only said that because you can't prevent all discomfort to everyone. Its not possible and there's a good chance fixing one persons discomfort will just make someone else uncomfortable, hence within reason.

And even so they should still speak up. Even if someone has some unreasonable discomfort (ie it makes me uncomfortable when you wear red) it may be so minor that it can easily be avoided. You couldn't expect people to not wear red, but if a co-worker said that to me i'd probably just try to not wear red.

Without communicating/talking about it, reasonable or not, there is absolutely no chance of the situation getting better.