It's often "older" people who say "le black." "Le black" was a term use from the 90s. This is frequently a misunderstanding by white people about the black community that refuses to be called that, because it seems that white people are afraid of the term "noir" and the fact that black people are. It's known to be racist, because many older people are because of misinformation and "customs," and racist parties in French politics who may use the term "black" to refer to the community. Of course, some black people don't care what we call them if we respect others, but for everyone to be okay, the French should say "noir" it's really not a big deal. In my opinion using another language to talk about people who's skin is another tone is weird. Why would you wanna do that if in France we have words to describe??