Between those options, I think gunmetal would look best. My del sol is gloss black with silver flake and currently has no vinyls/stickers/graphics and looks great. It actually attracts a good amount of attention, even when parked next to cars with crazy (and usually ugly) color schemes/excessive stickers/etc.

I am debating between painting my other car flat black (but I see it everywhere) or white (with a solid white interior). I even considered primer black with a clear coat for a slightly different flat black look.

I like all of those options except yellow. Please, stay away from yellow. I think it looks terrible on any car. Go with gunmetal.