I bred 2 CZFinch ponies and got 2 colorized only SO ponies, not CZFinch
I am guessing instead of one parent passing zebrafinch ans one pc or both zebra finch the both past pc so you got pc babies
Well first, you have twins
Second, I believe they both only passed on the PCol s-gene.
That can happen. There are two slots for the body Sgene. In this case both parents passed on colorize and neither passed on finch.
Oh and can I just comment on the amazing colors of those twins. I wouldn't a thought it possible just looking at the parent.s