Chicken colors question and hen rejecting her chicks of a particular color

Hi, I'm new here. I own a buff orpington hen and a blue silkie roo. My buff just hatched a clutch of eggs this week and 9 of them are a reddish-brown with black on their foreheads/backs, one is reddish brown, and three are a light opal/lavender color with a buffcolored spot on their foreheads. My hen rejected all the light color chicks and will peck and Chase them away but my roo has become very motherly, protecting them, showing them how to scratch, sleeping on the ground and allowing them to sleep under him.

Anyhow, I was curious as to the genetics of chicken colors and if there is a name for the chicks' colors and if it is normal for a roo to mother some of his chicks.

A couple pics

The reddish Brown w/black chicks in the foreground



The roo with the light colored rejected chicks