I started out in SL (2007) with a tan skin, with the intent to represent as a black avatar - "dusky" - in SL. High quality avatar options were slim to none for people of color. (I am white/black biracial in RL). I too was socially ignored until I began to wear lighter skin tones. Your dark skin will probably do much better in today's social-political scene in SL.
I strongly believe that anyone can be anything in SL, however I don't like the cringe-worthy, sexual objectifying of black men and women in SL by people that are role-playing as black "bulls", rapists, thug and black thot/hoe/***** stereotypes, and a variety of other bizarre interracial porn fantasies. I doubt that the majority of those type of avatars are controlled by real black people. Wearing a black skin in SL is not black face, unless you are choosing to wear a black avatar in a derogatory fashion with the intent to hurt us.