Good Porsche info, Mirrorfinishman
FWIW, Benz did sorta the same thing, doing their metallics in b/c first. They started doing it in the early '80s, and some of those b/c paintjobs had pretty thin clearcoats.
But my '85 Jag, painted "Rhodium silver" is ss. Kinda weird paint, I'd call it more of a metallic gray than a silver. But it's definitely ss, I got paint transfer onto my pads the day I drove it home from the showroom. SS metallics have a truly unique look, generally you either like 'em (as I do) or you don't.