Catalogued colours for
Whitefriars Ducks:
Flint / Amber / Sea Green / Sapphire Blue / Twilight /
Arctic Blue / Ocean Green / Ruby
Silver
FLC Aqua / FLC Gold / FLC Sky Blue
I am fairly sure this is the complete list.
It is known that there may be a few friggers in a couple of colours like Tangerine and another blue, but these are rare but still are unmistakeably the Whitefriars duck shape.
Hope this helps. Emmi
PS There are some very serious duck collectors on the Whitefriars site, here :
http://www.whitefriars.com/, who will be only too pleased to help with anything further.