Believing, or not believing, that sunlight will cause case colors to fade will not change the fact that the colors are a result of refraction, of sorts, that results from the surface structure of the steel after the case-hardening procedure. Science says that sunlight will NOT change the surface structure of the steel, so it also will not fade the colors. Read Dr. Gaddy's two part piece on case-hardening, that was published in DGJ, and this will become clear to you.
But, there will probably still be those who prefer to believe the myth. Abrasion (handling) changes the surface structure, resulting in the change in refraction of light and the loss of colors. I wouldn't be surprised if waxing doesn't CONTRIBUTE to the loss, rather than preventing it. Coatings, like the lacquers mentioned, protect the grain structure of the surface, thus protecting the colors.
It is worth mentioning, I guess, that loss of colors in no way means loss of hardness of the surface skin. The colors are simply a BY-PRODUCT of the case hardening procedure, and nothing more, albeit an attractive by-product.
SRH
