I think you are conflating two things. The prior exchange was (paraphrasing):
Poster 1: You cannot wear dark makeup because it is offensive to blacks.
Poster 2: Then that means that white kids must only portray white characters and blacks can only portray black character.
Poster 1: No, because skin color is not important to portraying a character.
Poster 2 (to which you responded): Then why is it important to paint yourself green when playing Frankenstein if skin color is not important?
A fair answer could be that since nobody has green skin, that is sufficiently unusual to be a defining characteristic of Frankenstein such that it helps the costume.
But, IMHO, dressing in a character by definition means to change your appearance so that it looks like the character you are attempting to portray. If you have white or black skin and you want to be Frankenstein, you change your skin color to green.
It seems a bit far to say that because at one time white actors used exaggerated makeup to play the stereotypical role of ignorant dancing minstrel blacks for the purposes of being deliberately offensive, now all makeup to look black must be shunned.
What else will we extend that to? As slavery was a horrible relic of history should no black man ever be in the employ of a white man because, even though he is getting paid, it is still a white man bossing around a black man so we need to steer clear?
I also again have the problem of who is setting the rules, who is actually offended and who is “offended” because that is what they are told to feel in modern society?
Like when Gov. Northram said that he told his black campaign manager about his Michael Jackson costume and was told it was offensive and now he realizes it was offensive. Was there an election that appointed Gov. Northram’s campaign manager the spokesman for black people? What if his campaign manager had said that he did not find it offensive? He and his campaign manager would have been mocked: “Ha, so his Uncle Tom friend told him is was okay, so he thinks it is! Ha ha ha!”
So just to get up to speed on things, let’s say I am at a gathering and playing Samuel L. Jackson’s character in Pulp Fiction. Is it okay that I wear: 1) the suit, 2) the gun, 3) the jerry curl??, 4) use the profanity, 5) mock the violence and absolutely everything else, but dark makeup is too far?
I take the point that I won’t look like Samuel L. Jackson anyways; I will look like a middle aged white guy trying to play Samuel L. Jackson. But that is part of what makes character dressing at these parties funny. When a five year old dresses up like Superman you don’t complain that he is far too short to be Superman and that he can’t fly. Likewise, the character is a joke and the attempt to be authentic is what is funny. But I can do everything except the dark makeup.
Now, some of you might throw a shot back at me saying something like “Being black isn’t funny or something to be mocked.” But in this case nobody is mocking black people; nobody is mocking Samuel L. Jackson. I am making fun of myself by pretending that I am a black character.