Basically here is what I meant -
Black is black, if it is doesn't look true black, it isn't black it is something else. (blue, brown, red...)
In the case of Your car, you are evaluating the factory paint. Not a great example considering the "black" used on a GN stock was some of the worst paint (in color consistancy and overall quality)ever sprayed on a production vehicle.
Trust me, we paint thousands of vehicles a year. If the paint is only black (no metallics, no pearls, no tints) we use the same black regardless if it is a Mercedes, Kia, Toyota, Chevy etc....
Also, Black is the ONLY color that can be panel painted and have it match with out blending or tinting. Wouldn't be possible if there were different "tints" of black.
I'll give you this: There ARE formulations of black. Can you tell a difference (when new)? NO.
The ones that have a heavy mix down aren't actually black. If you want the absolute "blackest" black, just use straight black....nothing else. It's as basic as it gets.