If that’s the case I’d guess that the pipe or sheeting or both are alloyed with a pinch of something making them behave slightly differently.
I melted down 35 pounds of roof jacks a couple days ago and cast them into ingots. They should have been pure lead, probably, maybe. They exhibited no odd colors but the sheet lead I mentioned earlier does at the same temp. I don’t know 🤷🏼♂️
