All the servo plugs on the futaba receiver (1,2,3,4) have the black wire pointing to the outside, away from the sticker on the receiver. Does the battery plug from the on/off switch have the black wire facing the opposite direction, toward the sticker?

NO... the polarity is the same through out... from the sitcker side... Signal(white, sometimes orange or yellow), hot(red, sometimes brown), ground(black, sometimes blue).

John