What colour will my ducklings be?

[newbie101]

Hi, I have some ducklings from black/white parents.  They are all different colours.  Most have a fair bit of dark chocolate colouring which I presume will turn black.  Some have dark brown and a lighter brown - almost like wild ducks and one is very different from the rest and is almost like a deeper fawn colour - does anyone have any idea what colour this bird will become?

Thanks!