Sorry, i hate to start my journey on this forum with waking up a 2 weeks old thread, but perhaps it's a useful tip for the future. At least here in Sweden a "lot" of paint-shops that do respray work on cars have the ability to use a camera with some calibration software, and a paint-mixer to reproduce the identical color of a paint years after production. Generally speaking it's used for matching respray-work with weathered paints. It never turns out great since the paint is in one shade, while the weathered paint is a scale fro one end to another, but it's better then going with the original paint.
Why would this be relevant? At least my local painter uses a rather fancy, but still regular system camera. With the right lens he's able to pick, and match the color of paint lines thin as a hair.

Your local paint-shop might have a bigger problem providing paints suitable for the environment then matching the color.

Hopefully i didn't just waste everyone's time.
B!