3 wires, one's green and the other two aren't colored. But the three wires coming out of the dishwasher are black, white, and green. I know that green is the ground wire and will connect to the green ground wire on the plug. Are the other two interchangeable? That doesn't feel right in my gut. How can I know which ones to connect to which wires? Also, why do they not do this at the factory? Thanks!