I know, right?? What a cool new color that could be!
After some digging I found this thread here on BYC:
https://www.backyardchickens.com/t/629394/magpie-call-ducks
Apparently, it's a rare quirk of genetics when you get a blue pied that's heterozygous for black (oddly enough that's also how you create copper betta fish, another animal I used to breed), but she says that the color isn't stable and won't breed true. But I'd like to give it the ol' college try and see if I can! Maybe if I can find a drake that's another wonky blue/black hetero, I can see what their babies will make. Since it's such an unusual color break, maybe she had no luck because there just wasn't another similarly colored hen to breed to.
I think adding a chocolate, or finding another rare mutant blue, could result in s'more ducks. Or it could be a waste of time. But either way, I get babies!