I am really interested in eggs color for both ducks and chickens. I know that there are many factors that can influence this, both genetic and dietary. My chickens lay a rainbow of dark dark brown (Marans) to blues, pinkish, green,(Easter eggers) and now teal to brownish greens from my F1 generation olive eggers.
Up until now my ducks, whom I greatly enjoy in every other respect, have been a bit of a disappointment in the egg color category. I did get a few passably black eggs from my Cayuga girls, but this late in the season (February) the best that I get is a light to medium gray. My Blue Swedish, Rouen, Peking and Khaki Campbell girls have given loads of delicious cream to white eggs. I did get one egg around last Halloween that had an orange tint to it, but it must have been a fluke (something she ate; maybe a leftover bit of something with orange frosting??) because I have never seen another one. We give table scraps sometimes to our birds, so something may have contained some dye or something. I have no clue, what happened, but to my great disappointment it was a one time event.
I ordered some late season Silver Apppleyard ducks (eBay) and hatched them out in August. They were all white eggs. (Yes, I am a sucker for hatching eggs.) I did not have a good hatch, and only two of twelve survived. One turned out to be a drake I named "Huey" and the other one was a duck named "Huette". Appleyards are adorable ducks, they always seem to look a bit sideways at you, and I was hooked on how cute and tame they became.
Anyway as Huey grew, I began to suspect that perhaps he was not a purebred Silver Apppleyard. He looked great as a youngster, but now he is indistinguishable from my Rouen drakes. Huette was always a bit darker, but looks more like a typical Apppleyard. Just this last week I started to get blue green eggs. I have gotten 4 of them. 3 of them we ate, but I kept the best one to preserve. It can only be Huette as the other girls have all been laying for a while.
My faith has been restored, there is such as thing as "duck egg blue". I am even considering putting Huey and Huette together and incubating her eggs. I am guessing that they had different duck mothers but may have had the same drake as a father.
Huey as a youngster...don't have a pic of Huette right now, if anyone is interested I'll post one: