As you know there are at least a zillion reds,perhaps even more.
If there is a good car parts place nearby,perhaps they might have a paint monitor(don't know the name of the tool) They will place it on the car where it is clean and take a reading where it should then what red you might have.
For example I took a 80 in to have checked as I needed the door painted after replacing the mirror and sagging hinge. He told me it was ....red. He made up a pint of the stuff and I had the door painted and unless you know ahead of time it is hard to tell.
I'd guess a dealers auto shop would have the same instrument/tool.
Chris