Mine is black-on-black, but I happen to like brilliant silver-on-black far more. After that, it'd have to be anthracite, dark blue, and dark green. I saw an earlier 129 in a mocha or copper color that was rather attractive, as well as a car in Bornite pearl that I considered at one point.
I've seen a fair number of 129s in teal, turquoise, and spruce/seafoam, and those colors don't really float my boat. I'm not much a fan of red or white either, but at least they're fairly sober colors that work on the car. There is a shade of red--a dark crimson--that looks really nice on a 129 that's in the neighborhood. It'd look better with a black interior than the palomino it has now.
I don't particularly care for the blue and burgundy interiors one encounters from time to time on the earlier 129s. The "neutral" colors--black, parchment, brown/tan/palomino, and grey, are best for the interiors.