Orpington cross

[HenHouse4Life]

I'm also wondering, would the lighter chicks be male?

 

[The Moonshiner]

I wouldn't say it is simple just because someone has breeding knowledge. You have to have some genetics knowledge. You have to know the genetic make up of both breeds involved and how those genes are going to interact when you mix them with each other. And even putting it like that is making it sound more simple then it is.
There's only a handful of genes that are sex linked and you have to pair the birds with them correctly to work in making sex links. Its not just putting two different breeds together. It has to be the correct genes on the correct parent and crossing with a pair that will produce offspring that will express the sex linked genes so they can be identified by sight at hatch.
The genes at play from your male extended black (which causes pretty much a solid black bird) sex linked chocolate. The hen is wild type which is the chipmunk striped chicks and the duckwing pattern as adults. When those are crossed the chicks should be black because the extended black is dominate and will cover the wild type. Usually the wild type pattern will show some bleed through when they're adults. Especially on the males so you'll get some color bleed.
The rooster carries chocolate that is sex linked. The pullets will get one copy from their father so it will change their black to chocolate so instead of a black chick they will be brown (chocolate)
The cockerels will also get a chocolate gene from the father but also a non chocolate gene from their mother. Males need two copies of chocolate for it to be expressed. Since they'll only have one they'll remain black. So that's your sex links. Males will be black and females will be chocolate.
Then of course you have to see what other genes are involved that may further change things. In this case you have barring on both birds so the offspring will all receive that and will be barred. Of course with chicks it only shows up with putting the head spot on the chick so that won't effect the sex link black vs chocolate.
Now their should not be anything else involved if the parents are pure that would further dilute the chicks or especially just some of the chicks to a lavender looking chick.
That's why we need pics to see exactly how they look to see what may be going on.
My suspicion is that your rooster isn't pure.

 

[gunslinger33]

I finally have some pictures.

They would be 1 week today

 

[ButtonquailGirl14]

I finally have some pictures.
View attachment 1760413

View attachment 1760414

They would be 1 week today

those look more black and chocolate barred!

 

[gunslinger33]

I thought yellow skin was recessive

 

[The Moonshiner]

Your rooster isn't pure CCO.
He has something else going on under the extended black I suspect.
The chicks aren't sex linked as far as the lighter vs the darker.
They are going to be sex linked by which have black (males) and which have chocolate (females) regardless of what else is going on pattern wise.

 

[gunslinger33]

What helps determine what is not pure CCO with him? Breed to a different color?Could impurity in my Biels have any impact?

Will the female’s color and pattern look like CC or more like my Biel hens?

 

[gunslinger33]

 

[The Moonshiner]

Are you biels impure?
If so then of course it could impact things. It wouldn't impact the sex linking in this case though.
My first suspicion with your rooster is that if pure for CC he would be a nice even chocolate with barring color throughout his whole body. Yours has a lot of lighter areas on him. Especially the hackles and back.which can point to something besides extended black being present.
The suspicion is confirmed when he is producing chicks like the lighter ones.
The female chicks adult looks are up in the air because IDK what genes they are carrying since unknown genes are in the mix.

 

[gunslinger33]

I bought my Biels as pure but you never know.

I will probably grow one out to see how they turn out.

Thank you for all the information