Baby ducklings

[Duck mommy 2019]

I have 3 yellow ducklings and one black one with the tiniest yellow under his chin. What breed are the yellows and which breed is the black? Thank you xo

 

[PirateGirl]

Do you have a photo?
Best guess without one would be that the yellow ones are most likely pekins and the black with the white spot may be a black swedish.