Most Mormon missionaries are white. I have never had a black Mormon come to my door. Jehovah's witnesses are more diverse. I have had black, Asian, and white Jehovah's witnesses visit.
I admire all missionaries of all denominations who try to spread peace and love in this very troubled world.
I read that the mormon church thru most of its history considered the black race a cursed race. Because of Cain.
When I was a missionary in England I had a black South African companion for a while. This was before Aparthid was done away with. We had a white South African in our mission too and they worked together for several months, got along fine. There were several other black missionaries there from various nations.
Well, my son had a black, Mormon for a football coach when he was in grade school. The family came from Mass.