Zombie Reply: The different colors themselves don't weigh much, but different colors require different techniques. Some colors require multiple stages and layers.

On the new ND, going with white saves about 15 lbs. That's significant on a 2,200 lb car.

 

Fun zombie fact - Mercedes, known as the silver arrow, got the moniker after removing the white paint from its racing cars, to save weight.

 

without seeing the numbers I don't know what to think about this but-

All other things being equal, I believe the black paint would be the lightest because carbon is an efficient pigment, a low percent by weight is needed to make something black,

White, silver etc need a lot of TiO2 and other pigments to get the look, Reds and blues the same.