Hey, I was just pondering writing an explanantion on the pied varieties of budgies, but I don't know EVERYTHING about them and probably have some of my facts wrong. So, I'll write (what I think) I know and other people can correct me and add on
It is harder to figure out the sex of a pied mutation as thier ceres do not turn the normal brown or blue. Usually, the female has a pinkish-cere and a kind of white ring around the nostrils. The males usually have more purple-y ceres.
The pied variety NEVER develop iris rings. Thier eyes stay the same, cute, full black from birth.
When breeding the pied mutation skips a generation, so the chicks will not be pied but the "grand-chicks" may be (I think...not entierly sure about this one)
I think that there are only two pied varieties (Dominant and Recessive). I am not sure about this on either
The colours can vary from Green, blue, white and "yellow" (I think
So anyone else want to add/ correct me, feel free