Tim Cole wrote:
I assume you are bringing the car to the place and they are using their spectrographic tool to do the match.

Okay so the next issue is the base the paint is going onto. If you are doing this yourself I guess you are making spray test cards and holding them up to the vehicle. Experienced paint guys with a good eye for color will take the material and test tints until they get what they want.

It's a time consuming process that body shops also experience because of things like fading and sun damage.

We were doing this Packard where the owner wanted the chassis to match the body. The painter made up dozens of test cards.

A few times I have seen an exact match on one part of the car and then way off on another part.

Some uninsured idiot ran into my modern car and I fixed it myself. I blended at the curves, but couldn't avoid one flat surface where there is slight blend line. On these modern cars they come out of the plant with mismatches so it's not a big deal except this moron hit me when the car was brand new and that was a total bummer.

A great example is the old Bill Hirsch engine paint. If you used a light color primer you would get a milder green that a lot of people really like the look of.