I tried my first color match the other day on the back of an acoustic and it went better than I had expected. I used this StewMac video:
I didn't do it exactly like this, but still turned out pretty nice.
Then I tried something similar on top(front?) of an acoustic and I could color match on one side of the light, but when I would view it from the other side of the light it was definitely off. How do you guys color match when you are repairing a cosmetic scratch/ding? I was kind of floored on how different the coloring was depending on the angle I was viewing the guitar at!
I'm new at this so I'm sure what "run out grain" and "book matched top" means.
It's impossible to color-match many natural-finished woods, especially spruce, because of the difference in how the wood looks with light from different angles. I avoid doing any sort of opaque touchup on natural tops. Even a deep clear fill looks better in most cases.
While you are looking up "bookmatched" and "runout", also look up "chatoyance".