On a 70 , how should the recessed area that holds the bumper be painted? I have seen some black and some body color but which is correct!?

My 70 Malibu was body color. Car was all original, and when I stripped it to repaint I found no signs that it was ever repainted. That area on my car is black now... as is the rest of the car ;)

Not sure if an SS would be different.

David