I didn’t really read the books, I just listened on Audible, so I have a tendency to miss details.
Yeah the green from the rust and since they are called “smokers” and they burn metals… the image of cartoon characters being so mad smoke comes out of their ears appeared in my mind’s eye whenever the books mentioned copper burning.
You can mark NSFW and then in the title state that it’s for spoiler purposes.
But yeah that’s a feature I’d like to see.