They have strip caulk on the back, because they're painted separately so water would get in otherwise.
Probably the same grey stuff used under the front fenders for example.
Considering the inner fenders are painted black, why black caulk wasn't used to blend in instead of grey sticking out like a sore thumb is a mystery to me.
Anyway, it is what it is.
The scoop block offs are black, not body color.
Some people just think they are because of cheap, lazy repaints with the scoops not removed from the car.