Australian Spotted Ducks Colours?

[rflagg2]

I have only seen a few pictures of Australian Spotted ducks.

Holddread's have pictures of a Green head Drake and Duck and of a Blue head Drake and Duck but only a Drake picture of a Silver Head.

Also can someone also show a clearer picture of the differences between the Green and Blue headed drake?

http://www.holderreadfarm.com/photogallery/australian_spotted_page/australian_spotted_page.htm