Red. Absolutely red.
I own a white Model S (the base white which is no longer sold, not the pearl white). I love the way my Model S looks, much more so than the pearl white that seems to be more common. The pearl white seems to be more a cream color.
I went and looked at a red Model 3 over the weekend at the Tesla showroom, and it's amazing. It's much, much better looking than I thought it would be.