Is my chick mixed or pure? Known parentage

[Tuppemor]

My broodies are hatching chicks for me right now, from my own eggs. I was hoping that some would be pure as I lost many of the parent birds.

Only two roos, faverolles and gold brahma. Possible mothers are gold brahma, faverolles, plymouth rock and black brahma.
The chick I am most interested in (the only one that looks like it could be pure) is an all yellow one. It has the right number of toes and the right color to be pure fav - but it has a dark spot on its head. I hatched pure favs last year, and one of them also had this - so is it pure, or can the father be gold brahma?

Pics and video will come later, if anyone wants to give it a go as for guessing who is what mix.

 

[Tuppemor]

Video of the chicks. I think there are three pure faverolles, as they are yellow with extra toes.
Any guesses on the rest? The one with a spot on its head is obviously a plymouth rock cross, but male or female?
Anyhow, they are too cute.