I like cars that seem to be different colors from different angles, but not when all the colors are visible at the same time. Cars like the McLaren are full of curves, so you can see all the colors from each angle. A bit busy and childish in a "look at me, look at me" sense, and not at all nice IMO. I'd much rather have a slightly more discreet but very nice metallic color--anything except silver/grey and dull British racing green or black--those are too boring and the black hides a lot of detail.
Mid to dark blues and dark reds seem to suit the non-HDF cars best. For HDF cars, mid blues and whites and oranges look great and are contrasted nicely by the black carbon fibre trim, sponsor stickers, etc., IMO.
TVR and a lot of other manufacturers can paint your car any color you like. As long as they have a chip to work from, or the paint mix formula, they can make the paint for you all day long. They like to charge an arm and a leg for this, though.