SS 396 cars had a blacked out tail pan and a blacked out body sill. What exactly are the body sills?

On SS cars theres stainless trim that runs parallel with the body between the fenderwells and is just below the doors. The space (below) the stainless steel trim is called the body sill. The color is a matt black color. This identified the car as an SS396 beast. Chevy wanted to make sure nobody mistook it for an SS350 car of which maintained the base body color for the body sill. Certain dark colors though did not get the blacked out treatment on 396s. Note in the pic that body color was applied to the fender below the stailess trim. This is a correct matt black bodysill.

Many thanks.

Thanks, is this true for the 68 ss 396? Mine is Matador Red,I know the tailpan gets blacked out but not sure on the body sills. Also is this same paint as tailpan ? ie; flat,semigloss,gloss,textured?Thanks again,Ed