Rick :

Fish in water with suspended sand , dirt,-- opaque water are often light colored . The fish's eyes sense all the light reflected from the particles in the water and above and through their chromatophores try to match the surroundings . In clear water they turn to their natural color. I don't know how dyed water effects this but the dye does stop or limit certain light waves from penetrating the water. I would be interested in any one with dyed water reporting on how the dye effects, if at all , the coloration of their fish . ewest