I have a Colt Combat Commander that is going to get some work done.
It is stainless right now.
I would like to coat it to get a gray color.
What to specify? DLC? What else?
This is a carry gun.
I don't want to destroy any of the roll marks on the gun.
Duracoat? I am going to DIY my rusty revolver.
Here are some examples :Golden Loki
nice info on site as well.
I'll be watching as well to see what comes up.
Not sure what finish you are looking for, but I have bead blasted a couple of stainless guns I have. They come out with a nice light gray matt finish.
DLC from IonBond looks great, pretty tough, and is becoming available in different colors. Contact Springer firearms (not sure their full title) for details or go through your gunsmith.
Melonite (re: S&W and Glock) is pretty tough and less expensive. Black only. You may not be able to do the small parts in it because of the heat used in the process. Search on 'Isonite' (I think) for an outfit that will do this for you.
Ceramic Coatings: Cerakote, Duracoat, and others are not as tough, come in lots of colors, and generally work pretty well. If aesthetics matter to you, I would have a pro do it. Seen lots of terrible looking DIY jobs.
Hard chrome: Probably the best overall for durability and corrosion protection but personally I hate the color.
I would go with DLC if you're worried about preserving your rollmarks. Ion Bond is much thinner that any type of "paint" coating so it won't fill your rollmarks. Ion Bond will take on the luster of the base metal below it while a paint coating will need the surfaced roughed up either by sand blasting and/or chemical etching such as parkerizing.
I would strongly consider Robar's NP3. It's electrolysis Teflon/nickle. It bonds with all parts inside and out with the exception of the inside of the barrel. It shows as a matte silver/grey. It is the best finish I have used. The gun stays slick and is very easy to clean. All roll marks will remain unblemished. I've had this on my Kimber since 2005. I have had zero issues. It will show ware, but it will be minimal and show as a polished spot. The NP3 is still there just buffed.
I had both my xd and 1911 refinished with duracoat. It looks great and has held up perfectly. I reccomend John Clemente at Mine Run Gunsmithing in Unionville, Virginia. He does exceptional work.