Everything already said
. The feather difference that is most important is the darker red over the wings, and the long pointy feathers just before the tail (saddle feathers) look at the girls feathers just before the tail, then look at the boys, there is a huge difference in feather style. Females especially black ones can have nearly as shiny of feathers and iridescent like the boys but that shape of feather is a dead give away he is a boy.