As has already been suggested by the earlier posts, there are multiple aspects to decoy realism. You don't want the decoys to be right on the edge of the marsh, because real ducks prefer to be more or less in the middle. Additionally, if the decoys cannot readily be seen from the air (for example, if they are too close to the edge of the marsh and the ducks are looking where they expect to find brother ducks -- in the middle of the marsh or pond or lake -- they might not see your decoys). You want to decoys to have some movement. On very still, windless days, this can be a problem. If your ducks are placed realistically and have movement (wind or some other source of movement), the physical appearance realism is probably less important. Also, it makes a difference as to how spooky the ducks are. In ealry season, ducks are rather naieve and easily decoy and respond to the call. Late in the season, it is going to be a different story. Back to the appearance of the decoys, I would be less concerned about the realism of the color and attend more to the surface sheen of the decoys. I don't think I would want "shiny" decoys.