Speaker cable

No, I am not buying it, it just caught my attention and so I asked. I think I have seen this kind of pairing elsewhere. 

thanks.

Electrical wire/cable is most always coded in a way to identify polarity. Sometimes its color, printing, or a ridge on the sheath. I think that is all there is to it.

Positive and ground are really the same thing. It's just a convention which is positive or negative. A circuit goes in both directions in each of the two wires. Therefore both should be electrically the same. Anything else is BS.,

Electrical conductors sometimes use copper for the hot leg and aluminum for the neutral and / or ground . This is true when they pull raw wire through conduit and when they put terminals on receptacles. The aluminum is cheaper, has a higher melting point, and the task is considered less critical to the purity of the voltage.  Often amps have a 4ohm tap, an 8ohm tap, and a common tap. The common tap is ground. Same idea. Not saying I agree with it, just offering this as a matter of explanation. 

I wouldn’t use it, but It’s probably copper Red and Aluminum black. It’s cheap and helps when plugging things in.  Like everyone else, I used lamp cord a hundred years ago and one side was smooth and the other had a line or lines on it. Sort of the same idea.