I see your point, engineer. I don't know Nina Simone's history but can easily believe darker skin matters, more or slightly less, in many ways including career, somewhat depending on where you are.
I live in a New Mexico city and rarely see any blacks at all. This is strange to me, and makes me question why the hell I moved here (answer: money complexities and that I had friends here.) Same with where I lived in northern California. My relative, whose mother was African from Africa (I'm vague on purpose), father northern european in heritage, was the last thing from scary in my Los Angeles area. Friends with their neighbors, and so on, in a middling area, mix of gang scenes, and mixed economic 'class'. Redlining was familiar. We had trouble getting a loan company even to respond, back in '76. Nods to AllState, or whatever that name is.
Now it's all super hot real estate. I and my ex are both sad, we miss the old place. Not entirely, lives move on, but miss it as it was. I've a lot of photos, if I would ever get my act in gear and post them.
As I've mentioned before, but, hey, she got treated as a whore by a trucker when visiting me in the north, when she was 13 or 14. I wasn't with her (walking the dog, for gawd's sakes, a doberman, not a chihuahua) but was plotzed. Yes, she dressed normal nicely.
Now I'll go look up more on Nina Simone (I can still hear 'first time ever I saw your face' way down in my brain cells/heart).
Back to the question, I get Tsar's take on play. But, they missed a bet. A closer reality could have been seriously good. I think Nina should have been portrayed more straightforwardly. Let me guess, there aren't all that many dark skinned actresses available at casting time - which points to the "system".