I found him in bed with a little green budgerigar sitting on his head!
The white is a blue colored budgerigar with a reduction in the color pigment and works in a similar way to the yellows.
Babies produced from this variety can only be a Dominant Pied or a normal budgerigar.
The original wild budgerigar known as a Light Green later developed Blues and varying shades of this color.
What cannot be taught is that natural eye for a good budgerigar.