Genetics Help: How to create a Porcelain Sussex?

[RcoM]

Hi all, the genetics are complicated at times so I need help so I am not wasting my time and money please if anyone can help?
I have mainly Coronation Sussex.
I saw hens described as Porcelain Sussex (clearly non standard) but pretty.
They are white with lavender necks but lavender speckles over the body- a touch of cream. Lavender tails

Would this be 2nd generation cross from a Speckled Sussex?

I am starting with 2 x Coronation roosters.

If so, should I add a silver speckled sussex hen or brown speckled hen to my flock or other? To try to create this colour combo.

Thanks in advance

 

[Amer]

G1 Cross Speckled and Coronation Sussex together.
G2 Then breed the F1 offspring together. Breed a LOT of offspring and you should get some girls that are both mottled and lavender based. This will be a very small percentage of the offspring. You may have to hatch 30 or more to get a girl with this color.
G3 To improve the pattern you can breed one of these girls with a Speckled rooster. This will give you some Speckled offspring that carry lavender.
G4 Breed the speckled carrying lavender offspring to get porcelains.

 

[RcoM]

G1 Cross Speckled and Coronation Sussex together.
G2 Then breed the F1 offspring together. Breed a LOT of offspring and you should get some girls that are both mottled and lavender based. This will be a very small percentage of the offspring. You may have to hatch 30 or more to get a girl with this color.
G3 To improve the pattern you can breed one of these girls with a Speckled rooster. This will give you some Speckled offspring that carry lavender.
G4 Breed the speckled carrying lavender offspring to get porcelains.

Unbelievably good knowledge. Thank you. Long project but definitely possible. Thank you!