Blue Ameraucana crossed with ??? created this...

[TeeMom]

Ok...here's dad, Roy.

This is a very poor pic of these pullets at hatch. They were both a dark blue with a faded yellow face. The one to the right had more yellow and she just looked so different from the start from the rest of the chicks.

This is a chick from my current hatch that is 3 weeks old and is the same coloring as the 2 pullets in the OP were at this age.

 

[BarredRockMom]

Oh for the love of Mike!! Is it just me who wants to snuggle those baby chicks or what!? Having little monsters around is so much fun. That coloring on the pullets & as they start to grow just gets more & more striking! So interesting how the genetics work & how Roy's input shows up in the negative coloration.

 

[junebuggena]

The down color of the chicks looks like what happens when you cross Buff Orpingtons with an extended black or birchen patterned breed. You can see that silver through the rooster's hackle feathers. So he's definitely where they got the silver base color.
https://www.backyardchickens.com/th...k-cross-is-it-a-sex-link.290379/#post-3536847
This thread shows a few really good examples of how Buff Orpington genes interact with solid black or birchen genes. See how similar the chicks look to yours. And if you can imagine replacing the gold base color with silver, how similar those pullets look in terms of patterning compared to your girls.

 

[drumstick diva]

Maybe you should call her " Gene" (Designer Genes)

 

[drumstick diva]

This shows the best side of mixed breed/color breedings. You touched the clouds.

 

[Lady of McCamley]

Here are a couple pictures I just took that show their full bodies @junebuggena...let me know if you need any other views. These were broody raised so they're quite wild, but we currently have them penned to try and tame them down a bit. View attachment 1128633 View attachment 1128635

The more I look at this, I keep thinking...Blue (the dad) throws 50% blue and 50% black.

These may be the black throw offs with Speckled Sussex mom's white inhibitor pattern???

Black could have over-ridden the mahogany, the white would have inhibited other colors but left the pattern (????)

While RSL may have colombian checked penciling (if that is the right word), I have never had any of my RSL mixes produce anything other than red with some very incomplete lacing and hackle pattern (the columbian).

But I have had my grey daughters (Splash Maran/Barnevelder) throw some really interesting stuff when the blue exhibits. (Otherwise, I just get jet black).

This is so totally patterned, in the same pattern tone of the SS...I don't understand the genetics of it...but I think it's something in that....black base from dad with SS white pattern expression from mom.

Very very pretty.

 

[TeeMom]

This shows the best side of mixed breed/color breedings. You touched the clouds.

Thank you...it was completely accidental, but was a happy accident!

The more I look at this, I keep thinking...Blue (the dad) throws 50% blue and 50% black.

These may be the black throw offs with Speckled Sussex mom's white inhibitor pattern???

Black could have over-ridden the mahogany, the white would have inhibited other colors but left the pattern (????)

While RSL may have colombian checked penciling (if that is the right word), I have never had any of my RSL mixes produce anything other than red with some very incomplete lacing and hackle pattern (the columbian).

But I have had my grey daughters (Splash Maran/Barnevelder) throw some really interesting stuff when the blue exhibits. (Otherwise, I just get jet black).

This is so totally patterned, in the same pattern tone of the SS...I don't understand the genetics of it...but I think it's something in that....black base from dad with SS white pattern expression from mom.

Very very pretty.

I will definitely have to test it out, just doubt that I will do so until next spring, but I will update if/when I can duplicate!

 

[junebuggena]

The more I look at this, I keep thinking...Blue (the dad) throws 50% blue and 50% black.

These may be the black throw offs with Speckled Sussex mom's white inhibitor pattern???

Black could have over-ridden the mahogany, the white would have inhibited other colors but left the pattern (????)

While RSL may have colombian checked penciling (if that is the right word), I have never had any of my RSL mixes produce anything other than red with some very incomplete lacing and hackle pattern (the columbian).

But I have had my grey daughters (Splash Maran/Barnevelder) throw some really interesting stuff when the blue exhibits. (Otherwise, I just get jet black).

This is so totally patterned, in the same pattern tone of the SS...I don't understand the genetics of it...but I think it's something in that....black base from dad with SS white pattern expression from mom.

Very very pretty.

Black doesn't override Mahogany. And Speckled Sussex don't have a white inhibitor. They have the mottling gene, which is recessive and produces white flecks. It has no effect on base color. The white you are seeing on these birds is SILVER, not white. Black is not a base color. It's a pattern gene. Dad is silver base color. Mom is red/gold base color with mahogany gene deepening the shade. Silver is dominant over red/gold. Mahogany will express regardless of base color.

 

[TeeMom]

The down color of the chicks looks like what happens when you cross Buff Orpingtons with an extended black or birchen patterned breed. You can see that silver through the rooster's hackle feathers. So he's definitely where they got the silver base color.
https://www.backyardchickens.com/th...k-cross-is-it-a-sex-link.290379/#post-3536847
This thread shows a few really good examples of how Buff Orpington genes interact with solid black or birchen genes. See how similar the chicks look to yours. And if you can imagine replacing the gold base color with silver, how similar those pullets look in terms of patterning compared to your girls.

Somehow I missed this link when you posted last and these chicks look EXACTLY like these girls looked as chicks! Thank you! Looks like I need to be coveting my buff eggs!

 

[Lady of McCamley]

@junebuggena
Great explanation of the genetics. Thank you.
Is there a book you like that is good to help understand the pattern genetics?
I'm ready to try to get my head around this.
LofMc