The one thing we can be thankful for here in Calif is the -mostly- dry air, average yearly humidity is around 25%. Not unusual to see 30-40 years old cars still doing DD duty with the original paint.
I read somewhere that Soul Red is a multi-step paint process and expensive to replicate; people that have had to have body work done on SR cars have related that their body shops had a hard time matching existing paint.
Ahh, for the days of single coat solvent based paint . . . You can take a 30 year old Miata, faded, and restore that paint to almost out of the factory condition with just a couple hours and a an orbital buffer...