The polarity to grey/blue grey/pink transposes dependant on the position of the window switch. I think this type of switch is called a double pole changeover switch. Im not sure if rover accomplishes this switching juju with a series of relays in the window lift ECU or with the switch (would be easy to figure out with a meter). Regardless of how the switching happens, the polarity at the lift motor connection should shift with the the change in the switch state. You should be able to get a test light to go with the switch in either posistion.