Maybe that's an idea for a future colour scheme - 'nicotine shadow', anyone?!
Still torn between black and SF, one has the retro nod, the other is very sleek.
My first SNES, purchased in 1992, never suffered with the yellowing. I eventually sold it in 1997 (stupid). Less than a year later I bought another one, second-hand, and that had some of the yellowing. I still have that one, carefully boxed and stored.