I had a 16 gauge Charlin re-case colored by Doug Turnbull. At that time Doug told me that case colors were oxides of organic compounds and subject to fading in sunlight.

I had no reason to doubt him, and didn’t ask for any proof.

I sold the gun to a friend, a serious sliding breech collector, who has kept the gun in a safe since the day he got it, maybe 25 years ago. I was startled how nice the colors still looked when I helped him move the safe to a different part of his house.

I have no proof, just what the guy who does if for a living told me, and what I have seen.

Best,
Ted