thought I'd post under the live steam section because the paint is to be used on a 7.5 inch gauge locomotive. Does anyone know the correct color match for Southern RR green paint as used on their passenger locomotives?
Not sure if you can find this 'off the shelf' but a technique I've used is to send a sample of the paint I want matched to a company such as http://www.match-it.net/ or http://www.paintscratch.com/. They will prepare a custom mix and guarantee that it will match. I ussed paintscratch.com to match paints on an Aster 232 U1 and was very pleased with the results.
Rustoleum High Performance Enamel in a Hunter Green gloss is the closest match you can get for off the shelf for SRR green. Other than that, getting a paint sample from the Southern Historical society and sending it to PPG or Paintscratch is your best bet.
if you have a color that you want, most auto supply stores have an instrument that can match the color. For example, if you bought a red car 4 years ago, the factory red color has faded a little bit due to the weather; the instrument measures the change and will give a paint sample that now matches the color of your car. I imagine they could match the color of any engine, car, etc.