Unnamed Man in Memphis Station

In "Lion" and again in Go Down, Moses this "man in uniform" (the story, 188) or "man in a uniform cap" (the novel, 222) approaches Boon in the washroom at the station in Memphis to tell him he he can't drink there, but in both texts, after looking "at Boon's face," he decides to say nothing. The cap suggests he may be a porter, in which case he'd be a Negro, but that isn't made explicit.