Originally Posted by bramblefir
The Buffs used in the original cross were the females, correct?
So with chickens the males have two "Z" chromosomes (ZZ) and females have 1 "Z" and 1 "W" chromosomes (ZW). The silver/gold base is sex-linked, meaning it only passes on the "Z" chromosome.
Here's the genetics for silver/gold:
S/S = silver
S/s = golden (silvery yellow)
s/s = gold
S/- = silver
s/- = gold
If your original cross was Lavender x Buff (always write as sire x dam, never dam x sire) the genetics would look like this:
Lavender (S/S lav/lav) x Buff (s/- LAV/LAV)
100% Golden-based Black Split (S/s LAV/lav)
100% Silver-based Black Split (S/- LAV/lav)
The golden color that your pullets have is known as "leakage". It's not because they are gold-based, it's basically "holes" in the black pigmentation where the red pigmentation comes through.
Crossing the male and female offspring of this cross will result in
Black S/S LAV/LAV
Black Split S/S LAV/lav
Lavender S/S lav/lav
Golden S/s LAV/LAV
Black Split S/s LAV/lav
Isabel (sort of) S/s lav/lav
Black S/- LAV/LAV
Black Split S/- LAV/lav
Lavender S/- lav/lav
Gold s/- LAV/LAV
Black Split s/- LAV/lav
Isabel s/- lav/lav
The next step to fix the Isabel coloration would be to cross both of the Isabel and then cross the best resulting Isabel male over his mother. All of the offspring from that final cross will breed true for Isabel.
As a slight correction to my previous post, you could get Isabel fastest by crossing a Gold Laced or Buff male over a Lavender female and then crossing the offspring (about 1/100).
I've got a Split Red Roo that I'm working to get the Isabel -
Red Cochin x Partridge Cochin Hen
Roo offspring from above x Lavender Hen
That Roo came out Red Split
Put above Roo to LAV hen, which the did create the Isabel on the Roos not hens and was incomplete unless they wound up with more color as they got older I don't know I had to rehome them -
So I'm putting my Red Split back to his offspring to put more Red into next offspring, should come out the Isabel even in the girls I hope and not just the boys