What you really need is someone with a spectrophotometer. You could take the part you want to paint to them, e.g. an A2000 top cover you want to redo, and they'll analyze the existing paint on it. Then they'll tell you what the code is. Some car painters do that, but lately companies like Benjamin Moore do so too. Check this out:
http://www.housebeautiful.com/shopping/gadgets/technophobia-color-matchingIf you find out what you need, please share it with the rest of us!
