Last year I took a photo of a flounder on a coral. It was mildly camouflaged but you could see it. When I looked at the photo more carefully I was surprised to see another flounder on the same coral. In the sequence below there are four images of the same photo. The upper-left is "straight out of the camera" and to the right of it is the same image rendered grayscale. In the bottom two I first restore the coloration of the obvious flounder (left) and in the other I restore the coloration of both flounders (right).