Blue face is a dominant mutation and I've had at least 10 chicks from this guy and several from his father who has nearly the same color, and not a single one showing blue face, so I highly doubt that's the case.
The ones that get this color do tend to start out a bit smaller than their siblings and I did loose several of them at just a few days of age as well, but the ones that make it to adulthood are quite sturdy. A note from my breeding diary, I think it's about this guy - he was 12 days old when I wrote this and had been adopted by another pair shortly after hatching as his mother was attacking him:
"The light colored chick has gained quite a few feathers, but it is much smaller than the two chicks it lives with and its wings are slightly droopy, as if the new feathers are too heavy. It is also peeping a lot for heat, its adoptive siblings don't."
I can't quite say why, but Im pretty sure the color is not silver based. I've been breeding on those ever since I joined BYC - I actually think I joined to ask what color the father of the roo above was. Never got an answer to that, and this roo is the first one I managed to produce with the same color (the father was less grey on his back though, more beige like a red breasted hen, but became more grey as he got older). I had to resort to inbreeding to have the color show up again.
I bought the first roo (CA) when he was about a year old, I was told he came from German hatching eggs, so I have no clue of the colors of his parents. I then paired him up with a wild colored hen I bred myself. From this pairing, I took a wild colored hen and bred her back to her father. It took a while as I don't use an incubator to hatch the eggs, I let the hens hatch them on their own, and CA had a horrible fertility (like 1-2 chicks from each clutch). Eventually this guy showed up though, and a normal red breasted hen as well. CA died about a year ago, so this guy is continuing his lineage and he has a much better fertility. Despite using inbreeding, I never saw an obvious silver chick from these guys. Normal red breasted, darth vader, wild colored and then those pale ones I'm not sure what to call - that's all I get.
