Hmmm, as a fucsian myself, I think to see that one of the main points of being blue is to announce it and constantly attest to the fact. But this usually is done at a place that Blue's go to to do just that.
As a practicing Blue (I'm assuming I'm correct), I've never been under the impression that one of the main points of being one is to announce it or constantly attest to it -- the main point is to live a life following the doctrines of being Blue. HOWEVER, I would agree that there are some branches who practice otherwise (just saying that not every Blue branch believes in being soapbox preachers, KWIM?
I could see if somebody was under the impression that everyone in the room was blue that it would be ok to do the same thing only Blues do.
I think it would have been horribly rude if Aunt knew someone wasn't and still wanted to do it, or if she was trying to "out" someone - then she'd be evil.
Forcing everyone to declare he/she is Blue is not okay and if someone thinks everyone is, then, really, it's unnecessary. To me, that demand is in order to out someone's belief system, which, I agree, is evil.
As a Blue, I whole heartedly agree with this!