ADDITIONAL GENETIC INFORMATION
Erminettes are currently gold based birds. Individuals who wish to show their stock will need to keep their males out of the sun so that the white feathers stay white on the hackle and saddle. If they are allowed in the sun the white feathers on the hackle and saddle will gradually turn gold from being exposed to UV rays. Silver based birds will not do this. If there are silver based individuals in the Erminette I have not yet seen them.
Getting the proper skin color is challenging when white skin is prevalent in the flock. The reason for this is that white skin is sex link dominant and yellow skin is sex link recessive. In short, not only do the typical dominant/recessive rules apply, but adding the sex link feature means there is added force set against the yellow skin color. Keep in mind, the male carries two genes for skin color (which can be in any combination) while the female only carries one. Whichever color the skin is of the female is the color of her one skin color gene.
Achieving the proper leg color can be challenging due to the combination of the skin color with leg pigment below the skin. The following examples clearly lay out what is happening when you see certain leg color in Erminettes
White skin without pigment under the skin will result in pinkish white colored legs
White skin with pigment under the skin will result in blue-slate colored legs
Yellow skin without pigment under the skin will result in yellow colored legs
Yellow skin with pigment under the skin will result in willow colored legs
When dealing with the white colored Erminettes you will always get clear yellow legs because the two doses of dominant white block out any pigment from appearing on the legs. With the Erminette colored birds you will find some with the proper solid yellow legs and others that have some leg pigment present under the leg skin on the shanks and toes. Usually this pigment extends down the shank and ends at base of the foot or half way down the toes. The remainder of the toes being a clear yellow color. This results in birds with willow colored shanks and possibly partial willow colored toes. Modifiers determine how much black let pigment will be expressed under the legs and toes. Now, on the Black Erminettes so far all have appeared with a dark willow to almost black colored shanks and toes. This is because there are no dominant white genes to restrict the expression of black leg pigment.
Added Breeding Challenges
To summarize; the existence of some birds that crop up under standard weight, off colored stock, struggles with proper skin color and leg color, modifiers which create unpredictability, combined with the normal rigors of breeding to a set standard; one will quicly realize the challenges which face any individual who decides to take on this breed. And all this has only touched the traits effecting color and type, we haven't eve touched productivity yet.
These challenges make it much more difficult to produce consistent stock than someone who's breeding a Buff Orpington for instance. There are already enough challenges in breeding stock which has been bred and selected over a hundred years to a specific type and color (Like the Buff Orpington). So taking on something like the Erminette will no doubt take decades of steady breeding if not generations of men and women who steadily breed toward the standard before we get to the point where it can compete with the standard breeds. You can quickly see how the goal of maintaining productive birds which adhere to the standard can take many years for a breeder to achieve. Such birds are highly sought after and are worth the premium in price they command.