I had saw the entire FMV.The water is allways there.I think I already understood what you are talking.You are talking about little pixels "Squares" of color which creates the image.I already noted the change in color even before posting it.
But never saw the color of the channel change into the land color(or the opposite)
You know,light colors donīt change into dark colors out of a sudden.
There is an higly difference in the tonality of the land and water colors.
Light colors change to light colors and dark colors to dark ones.And the tonality change is always little.