Australian Yellows with purple feather on chest

[Sunset bee eater]

Hi

I have these two Australian Yellow cock birds? They have some purple feathers on their white breasts and the white headed Australian Yellow has a few black feathers on its head while the yellow headed bird has a number of lighter feathers on its head. Can anyone tell me why this has happened?

Many thanks

Emma

[finchbreeder]

The Black headed Australian yellow Gouldians head becames predominantly white due to the diluting effect that makes them yellow with a white chest. Hence the "white headed" Gouldian is in fact a Black headed gouldian so the black feathers are not all that strange. Purple shading in the Australian yellows chest is considered a fault by many. However it is apparent to me that the Australian Yellow Gouldian is in fact a form of pied, so this is not all that surprising that the chest will from time to time not be pure white.
LML