Thank you, youngtug. I have seen green copper things (copper bottom saucepans can be so insightful).

I didn’t know that air and moisture caused the reaction.
There definitely isn’t any green on the item.
Thank you for the explanation, youngtug. I thoroughly enjoy learning new things; I’ve always been inquisitive. (When I was in college, I took required courses and deviated from my major to also take unrelated classes, eventually earning a degree and two certificates. Apparently, I had too much time on my hands.)
Update: insightful should be delightful. Autocorrect can be irritating at times.