Mutts?
Maybe post the pics in a new thread here,
https://www.backyardchickens.com/forums/what-breed-or-gender-is-this.15/
someone may know what they are.
Try to get side, top, and front views of each and label them with a number.
Anyone can call themselves a 'breeder'....
...and google images are not always accurate either.
Here is a Welsummer female and male at about 14 weeks.
Crested Cream Legbar pullet:
They are supposed to be a dark reddish brown, often called terra cotta. But not all lines lay good color.
No, it could not.
It could be some kind of stressor.
How big is coop and run, in meters x meters?
Dimensions and pics would help.
What all and how exactly are you feeding?
That was my first...