I'm tempted to let you figure this one out so you will remember it, and understand it!
In terms of function it doesn't matter if they are reversed. The needle will then point toward charge during starting and toward discharge while recharging. The ammeters I've seen on are only stamped with the R for Red.
L few optional items will occassionally be connected at one of the ammeter terminals. Clock, Convertible top motor, rear window defrost grid (along with heavy duty wiring), etc.