I'm not trying to be rude either, but rather trying to educate.
What you are suggesting, Buff Goose Guy, would be SO highly unlikely. It would mean that the mutation would have to occur in one of the sex cells before dividing, the hen or drake with the mutation would have had to donate sex...
Yes, it looks like you may have gotten mixed ducks of mixed ducks. I don't see any that look pure..... Sorry, not even yours. The eye stripe is wrong for a Rouen.
If you yourself are happy with the ducks, and want to breed and sell, by all means, go right ahead. Just don't sell them as pure...
That's what I would do. Keep in mind though, that it is very possible that you have some hidden recessive genes going on, such as recessive white, dusky, light phase, among others, so don't be surprised if you get some.....surprises.
If you really want to know and understand what is going on...
Oh, and.....
Assuming that all the ducklings have the same mom/dad, and that they are Saxony/Rouen cross, and that each carries the white gene, statistically your outcome for 10 ducklings should have been:
2-3 white
3-4 grey (Rouen)
3-4 blue fawn
But....
Since there was probably a pekin...
Since we don't know your breeders' set-up it is impossible to know exactly what outcome should be expected from her crosses. If she doesn't breed in strict pairs, then it is possible that your little flock has multiple moms/dads. It could be that only one of her saxonies, and one of her Rouens...
Sure, I have lots of ideas.
If a saxony X Rouen made a white bird, then neither can be a pure saxony or Rouen. There was probably a pekin involved somewhere.
I'm not sure what you mean by "silver grey", except that you may be talking about "blue", as in Cumberland blue, a common color for...
Yes, rouens come in a color called "Rouen Clair", which is a trout phased Rouen. Asside from that, I believe that in order to prove that you have pure rouens you will have to do some test crosses because I honestly don't think that most people will believe that you have had 2 similar mutations...
Well, you are obviously going to believe a lady that sold you some hatching eggs in a parking lot rather than taking advantage of the wealth of knowledge that can be found here from long time breeders such as myself that have been breeding rare colored ducks for 15 years. Congratulations on you...
So...
It takes 4 weeks for duck eggs to hatch, so they could have come from this hen if they hatched 4 weeks after she died.
And...no, blue is not a simple recessive gene. It is incompletely dominant, and if either parent has this gene it it would be plain as day. They would look exactly...
Yes, I know about the variations in Rouens, but you cannot get a blue Rouen from 2 regular grey parents. It is impossible. You can, however, get them from crossing a saxony and a grey Rouen. Could it be that the hen that died left some eggs that were hatched by another duck?
Could very well be a saxony cross. If runner X, what color was the runner hen? There may be all sorts of hidden recessive genes, and you will end up with a hodge-Podge of colors and patterns.
Do you have pictures? If they are truly blue fawn then you should get regular, blue fawn, and pastel rouens from this cross.
Do you know what their parents were or looked like?