Well if your doing black people, don't be afraid of the light. When newb artists do white people there's a large tendancy to darken the background to help bring out the whiter color, simply because it's a quick fix to contrast issues that plagues the composition. With black people, it's easier to work in brighter enviroments because of the contrast (it's easier to see them during the day then night compared to white people). Well, atleast that's my opinion on the matter.
I'll edit it in photoshop to show what i mean.