Any decent paint shop should be able to match the colour almost exactly with an optical scanner, if your really fussy a bit of research to find out what type of paint used and get that type. If you know the original name and year of the paint, they should have the exact recipe in their code books to mix up the right colour on the spot. Not hard to paint it yourself, terry has a great thread showing what you can do with a spray can and a fuel tank.
Cheers
Troppo
With respect...
Yes an optical scanner can match the color. What it doesn't do is match the process...
Hence you lose depth.
Modern one step paint just doesn't look right.
Its not a matter of matching the code. It requires the original paint plus the top coat (candy) to get the desired effect.
For example here in the US most paint shops don't even carry the correct metal flake size as everything has gone to micro flake
Mirco flake being easier to spray thru guns, keep in suspension and flows more uniform with regard to surface uniformity and coverage