Black and white or black and lighter anime duo?

Me and my sister are trying to figure out what to cosplay for next year's momocon.
I know I wanna be black.
So I said: "knuckles from sonic.", "gunsmith bitch from panty and stalking." but, both times they said: "What would I be?"
So I've decided to turn to mangago for help.
Does anyone know any anime black and light skinned duos me and my sister could cosplay.