All the babies will be bibbed by the looks of them.I posted a bunch of pics of them here: https://www.backyardchickens.com/th...black-runner-duck-pics.1456235/#post-24246202
There are definitely some dark grays (blue?) in the litter, there are some light grays, and some weird "mauvey" looking ducks that have like this even almost rust-colored head!
What is bark blue?? Sounds pretty!
Looking at your blue bibbed, I'm thinking my ducklings may be bibbed as well! The Extended Black mom has a small white patch on her breast which I didn't think much of but now all her babies have a broken runner pattern where the white from their neck continues all the way down all their bellies!