Colour looks a bit flat and boring to me.
I know what you mean, but perversely that's the appeal to me. Since I'm not lucky enough to own a genuinely vintage patinated car, I like the old-school combination of a flat colour on something with curves.
(When I recently picked up a car with special order 'Tweed Grey' paint - a BMC flat colour - I was ribbed by the guys at the Malvern paint shop saying "do you want us to put a top-coat over that primer?")
