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 runners. This, crossed with a Rouen would result in a blue-fawn bird.
saxony X Rouen would also result in blue-fawn.
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 runners. This, crossed with a Rouen would result in a blue-fawn bird.
saxony X Rouen would also result in blue-fawn.