Where did the sex link come from?

[RWise]

Ok this is this roosters first hatch, he is from a silver splash rooster * and a BA/EE (75/25 per breeder). He is black in the shade and blue-green in the sun! I call him Slick.
My hens
1 The BA/EE above, with this black EE rooster
2 His sister from the same mix. (ya ya I know, I just got a new rooster for fresh DNA)
I expected to, and did get black chicks!
3 Red EE/FBCM
These are chocolate brown.
4 GEM (Green Egg Machine) CL/WL, purchased under this name.
These chicks are yellow, so far feathers look yellow, but I think they are white.
5 Blue Ameraucana, said to be full blood from someone that shows them. This is the silver splash roosters mother.
I think I have black chicks from this mix.
6/7 EEs from the silver splash and other EEs

So, where did the black chick with white spot on its head come from? It and 2 others already look like boys, but they dont have this spot, and only 1 is black.
Or could this be just a random spot?
*I should note, I suppose, the the silver splash roosters daddy is a Bantam Silkie Frizzle.

 

[Ridgerunner]

With your chickens who knows what is going on. With your mixed breed chickens the genetics are so mixed up about anything can happen but you can't depend on anything. Most of the names you are using don't tell me anything about what genetics go into their genetic make-up. All the hens are mixes anyway.

Can you see if there is any barring on any of your hens? If so that points to the mother since your rooster is not barred. If some of yours are white you might not be able to see the barring. The chick with the spot probably is a male and you just got lucky that the genetic mix from the parents allowed a the spot to show.

 

[RWise]

I have only 3 white hen/pullets, the 2 GEMs and 1 Delaware, but did not set any of her eggs. I had some bared rocks, but all of them and their offspring are gone. I certainly got sex-links from the BRs, and the big red guy.