Duck question

I was out roving the Bailey Tract this morning and had great conversations with folks I met along the way. One person mentioned the Mottled Ducks with one having a different colored bill. When I got hope and looked at my photos - I could see what he was talking about. Please take a look and share your knowledge as to the reasons for the different colors....could it be one of those Hybrid Mallard that I had heard about?

 It was very foggy this morning - so the colors are not the greatest.