Green’s Dictionary of Slang

bone n.7

[bones n.2 ; they are also ‘black and white’]

1. (US Und.) a black person.

[US]A.J. Pollock Und. Speaks 11/1: Bone, a negro.
[US]C. Stella Jimmy Bench-Press 78: You ever hear this kid talk? [...] He’s an articulate bone.
[US](con. 1973) C. Stella Johnny Porno 126: I hope somebody shot this bone after they made the movie.

2. (US black) a person of mixed race, esp. Anglo-Irish-black.

[US](con. 1940s) C. Major Juba to Jive 52: Bone [...] used during the forties to refer to a person of mixed Anglo-Irish-African ancestry.