Leo is into hip hop and is cool with a lot of black folks...that's about it.
Also he's been passed over for Oscars a lot, some suspect that it's because he's not part of a certain sect of Hollywood, the conservative old heads. He's also very big on political issues that would be considered progressive.
Plus Leo keeps to himself most of the time...catch him on an island with 10 dimes and a few of his boys, smoking joints and giving zero fukks.
I don't know about that honorary thing but it's not sin for white folks to be cool with black people.