Off black paint for scale effect.

[Ulf]

I'm also quite convinced that the scale effect is quite small on the type of cars we build, but it's very much a matter of references. If you choose to paint with a broken black, e.g. black and skin color (pink type), you can with the full black blur what should not be visible, e.g. a not detailed wheelhouse on a slammer ...
A little OT, my dream in professional life has been to build a house where the color black is prohibited, high up among the project goals because the deep black details are like holes when you look at the finished house.

[Richard Bartrop]

For a 1/24 scale car, it's like looking at a car that's across the street, so unless you're looking at it in a fog,  any atmospheric effects are going to be effectively zero.