I bought an 18 gauge 3 prong grounded electrical cable from Radio Shack. It's a replacement cable for electrical devices. This is theNorth American standard cable. Anyway I want to confirm the color coded wires before I go ahead and hook the cable up. I'm used to black being ground and red being hot. But this cable has black (again I assume this is ground), white, and green. Can someone confirm what these color codes refer to?