I certainly don't know any of the current Reds personally, nor could I even name any of them, but has it occurred to any of the disapprovers that it is quite possible that one or more of the team is gay? And if not, then if the team survives long enough then statistically it is quite likely that there will be one some day.
Personally I've always found gay pride events rather silly, but I'm all for the Red Arrows flying over London, or anywhere else for that matter, whatever the pretext.
I like P-N's rainbow smoke idea. Shouldn't be beyond the wit of man (or woman, the RAF does have female engineers) to sort it out.