I've asked this question with no results. Has anyone experienced a blacking of case coloring. I had my Smith Trap Grade 10ga. cased. I set it aside and all was fine for a couple of years then it turned black. The coloring is there but it is very muted by the black color. I feel like all it needs is a good cleaning and that will wash away the black? I have removed the protective lacquer in the belief it was the protective coat, it seems to have helped a little but its dark!!