MTG, Midnight Banshee Effect regarding hybrid creatures?

Question

So basically all I want to know is if Midnight Banshee's effect about putting a -1/-1 counter at the upkeep on each non black creature would effect a blue/black, green/black, red/black, or white/black creature. Seeing as they are all black it seems to me that they would not be affected, but since they are also other colors making them non black I second guess myself. Please explain, I've been thinking about this one and it's not too clear.

10 Points all for you best answer wins.

Answer 1

Since the cards are half black, they are not effected by midnight banshee's effect. For example, if I play a red/black card it will not be effected.