Blue, Black, Silver
Silver (also called Lavendar in Europe) follows the same rules as Blue, Black, Splash in chickens. Silver is a color and there are several patterns possible including Bibbed, Magpie, and Splash.
Chocolate
You can also use black in place of mallard in this chart.
Drakes can "split" to chocolate, but females do not. They are either
chocolate or they are not.
Butterscotch, Blue Butterscotch and Appleyard
Crested Duck Genetics
Snowy Hen and Drake
Spot Hen and Drake
Aleutian Hen and Drake
I have not bred or owned an Aleutian. This photo is from the Call Duck posters on the National Call Duck club page
Yellow Belly Theory
Nobody really knows how the inheritance of the Yellow Belly call works.
This is just my theory and I welcome any input from our European friends. I have posted this to the British call duck facebook groups, and thus far have not heard any instances where this chart would not be accurate. If you have experience with yellow belly and want to drop me a line I would appreciate it!
I have been told that the instance of yellow belly seems to be stronger with 2 copies of the gene. (See chart #2)
This color is not widely available in the US