In hindsight I will say that my comment about desaturating nighttime scenes could probably be taken out of context; I agree that making dark skin look gray is probably not the right choice. I just meant that there are techniques to making colors look darker without having to make it invisible on certain screens.
The references from @theyrebothakilogram's post are a great example. All of them read as very dark, but I can still see them on my monitor, because the artists were able to utilize techniques that make the colors look darker without using a shade at 7% brightness.
But I'm white as a sheet with not as much experience drawing darker skintones, so that's about as much as I can say on the topic, lol.