Oh goody!It wouldn't be sex linked unless it was the other way around. Blue over cuckoo would create blue girls and barred boys and yes the egg would be more olive but as I understand it the Dark egg layer over the Blue would tend to give the best olive color.
I need to start checking fertility of my ArkBlue & Cream Legbar eggs now that I have a French Black Copper Maran roo.
I'll love to hatch me some girls that will lay dark olive eggs!!
Yay!
