Hollywood has a thing for coupling black men, particularly dark skinned, with any woman but a black woman. In this film, the leading male, Apollo, is supposed to be a biracial man, but he is portrayed by a black man, who at a minimum should be light skin. His love interest is supposed to be a black woman, but she is portrayed by a biracial woman. This is the typical racist model that Hollywood uses to represent black people.
Black men must have classical African phenotypes and women cast as Black must have white or biracial phenotypes. Light skinned black men and brown/dark skinned black women are consistently excluded.