Colorful duck

Thursday
Early morning mist gave way to a beautiful sunny warm autumn day. It was late afternoon before I got out for my walk, my usual route, down to the river in Vulaines, along the river to Héricy, then back along the upper road. I was watching the swans and mallards, when I suddenly spotted this colorful duck. I'm thinking it is either a juvenile male mandarin duck or a male mandarin going into "eclipse" plumage - can anyone help me out?