The Hook Bill is a light duck, with an average weight of approximately 2 kg. Three colour variants are recognised in France, the Netherlands and the United Kingdom: the dusky mallard has a black head and rump with green lustre, the body in shades of grey with no white neck-ring, and a slate-grey beak; the white-bibbed dusky mallard is similarly coloured, but with a distinct white chest-bib and white-tipped wing primaries; the white has pure white plumage, blue eyes, bright orange legs and a flesh-pink bill. A further seventeen colours are listed for Germany by the Entente Européenne, but are not accepted in the European standard.[8]