Speaker cable

Can someone tell me why positive (red) cable is of copper and the return (white) is of whatever? It could be sliver plated, but why is it necessary, what does it add?




Aluminium is my favorite one.


Really? Aluminum for speaker cables? 🤦‍♂️

I remember decades ago buying spools of speaker cable at Radio Shack . One leg had a silver look. Strictly to identify + and - . Don't think it's any more than that.

@ron_hartman .. but marking the cable, instead of marking the cover is a strange way of identifying it, would not you think? And I wonder if this indeed is a copper, and not something else as the substitute. Nevermind the lamp cord, but this is the cable for the entirely different application altogether.