Can anyone (preferably Dan) tell me if colored coatings are different than the black coatings (besides color)? I ask because after buffing the edge of my gray S5, I used some lacquer thinner to clean off the buffing compound. While I was wiping it down, I noticed some black/dark gray coming off of the blade, too. I thought it was just dirty compound, so I flipped the paper towel. Still, more black/dark gray stuff. I then tried scraping the coating with my finger nail and it felt a little soft. What kind of coating is on these blades? If it were a baked on epoxy, it seems like lacquer thinner should have had no effect. I've wiped down my black Dog Father with lacquer thinner and never noticed any softening of the coating. Any info about this?

It could be a primer, but that's probably decarb. Heat treatment tends to cause carbon to migrate from the steel at the surface; that's decarburization. The first round of Competition Finished INFI knives left the decarb on the knives (the CF trade-off was that you got a fully convex edge but they didn't finish the blades to reduce production costs). Unfortunately, decarb is a thin layer of very high-carbon steel residue that is very vulnerable to corrosion, so on the last batch of (BWM) Competition Finished knives, they also made a point to remove the decarb -- those CF BWMs are OUTSTANDING knives.

It's the outside of the coating that seemed to soften, though. It wasn't something under the "main" coating.

I misunderstood what you were describing; I don't know. I do know that some of the coatings have different textures and that some wear better than others, but sometimes the color choice is worth it. I think that Arctic White is basically automotive paint.