Washing machine cord- only green wire- other wires do not have colors?
First, are you using a heavy enough line cord? Washing machines are fairly high draw appliances owing to the motor (and water heat if equipped) and should have at the very least a 14AWG if not 12AWG cord -- or whatever the previous cord was if you are positive it was the factory cord. In my experience, those cords come with 3-color wires, and usually light 16AWG cords don't color.  Just indulge me and check to be sure. 

Granted, I have seen thick extension and appliance cords that are flat.  However I am used to the conductors having colored insulation . 

If you have a flat cable such as that, with no markings, look for either ribs on the edge of one side, or the cable lettering  or a stripe on one side.   Follow it down to the plug (the tall pin is the neutral) but typically the neutral is the ribbed, striped or lettered side.   Ground is in the middle.