Of course silver oxidizes at room temperature. We don't polish it before a festive meal just for the heck of it, eh? And the black residue on our hands isn't sulphur, either. (Imagine if your silverware smelled like rotten eggs?!)
If ACMe's using 200microns (quite thick) then I doubt that you've burned through it with contact-sparking each time the fridge's compressor kicks on, nor worn it off from abrasion. But orange? Does sound like brass (copper)....
Maybe you should smell the ACME. Eggs? Ha!