I've learned the hard way to "never say never" in genetics, haha...there are too many unknowns, modifiers, unexpected interactions and linkages, etc. For example, I used to say that if you bred two (recessive) rex-coated rabbits, you'd always get rex-coated kits. Until I discovered that there is not one, not two, but at least three different genes that produce that coat type (that we know of so far)! And they don't always cooperate with each other to make a rex coat... so you *can* get a normal-furred rabbit out of two rex-coated ones!
I absolutely love the Champagne d'Argent - it's the only breed that might pull me away from Satins! - but good luck with Champagnes as a "simple" color. Even though the silvered breeds are very old, the gene for silvering is one of the less-well-understood genes; in fact as far as I know it hasn't actually been directly identified. It appears that it may be partially-dominant - sometimes the silvering effect is seen in heterozygotes, sometimes it's not - and the amount of silvering seems to be heritable, but that may be due to differences in the genes themselves, in modifiers, both of those, and/or something else. And since Champagnes are black-based, which is dominant, you can't rule out having a different color (blue, brown, or lilac) pop up if there's been an outcross with a rabbit carrying chocolate or dilute, even in the distant past.
But what fun it is!
Genetics geeks, unite!
