GrannyCarol-
I just read over the bulletin again. It just states that there is variability in the gene pool of Appleyards. The adult males can have white on their faces or be almost solid green. I have talked to Dave about the males and he has said that when selecting breeding males oen should look for a soild white ring around the neck and flecking of gray and browns in the face as well as white. The adult females also vary. I have no problem telling them apart. I do have a female that looks like it could be a cross between a Saxony and an Appleyard but is a purebred. She is darker than the other 5 ducks. When she was a duckling, she had a wider black mohawk on her head. I would be interested in seeing a picture of your to see if it looks anything like mine. I have a friend who also has a darker Appleyard female. This female did not display the thick mohawk though when she was a duckling.
There is variability in the breed like there is in Welsh Harlequins. In addition to the "Rouen like" coloring in the plumage that can be displayed at times (like I noted in the previous reply), there is also a pure white version. This is also due to the Silver Appleyard genotype and is common. I have had one before any they are beautiful! They have similar plumage to a snowy owl. His name was Moby Duck. When mine was a duckling it had no mohawk at all but did display the black tail. I have read somewhere that typically the ducklings should display the mohawk but do not always.
When breeding one should select away from the darker, white, and "Rouen like" birds if they want to breed true to the standards.