One trip-up point for non-electrical people is that they are more likely to have been exposed to automotive wiring in day-to-day life, where red is hot and black is ground. (+/-) I actually had to argue with a friend about this, who was convinced black was ground or neutral. No, he wasn't doing any electrical work at the time, and I advised him he never should. (US)
I find it interesting that in HV power on hybrid cars, Both + and - are orange!
This all dates WAY back. In the beginning, wire was insulated with rubber, and the rubber was black. The writers of the early issues of the NEC decided that all wires should be assumed to be "hot" EXCEPT the identified, neutral/ground, conductor, so the mfrs. painted some wire white to identify it, and the "white/neutral/ground" business started. Now that we have rainbow-colored plastic insulation, the "Identified" wire is still white (and every other color is assumed to be "hot") (except the green/ground business which came much later.) The ribbed side of zip cord is considered "identified," so, that's the neutral.