I feel the best way to match any paint color is to take your rolling stock sample to a paint store. They will have a reflection densitometer that can match the color.
I feel Home Depot does this process the best. If you are painting structures a latex paint is great but if you are doing rolling stock and have an air brush, an oil base paint would be the way to go.
An automotive paint shop has the best reflection densitometer and skilled operators but the prices are extremely expensive. I have used Napa Auto Store Paints but still expensive.
Below is a Fun Color Matching APP from Home Depot: Going to the store is better.
Color corrected lighting.
What the APP sees. Needs some fine tuning at the store. Take the picture with the Project Color APP from Home Depot.
Gary
