At the aquarium in Chattanooga, all RES have washed out color. Seems I've seen RES in a BassPro aquarium and it was pale and without out enough color to readily idenify it. Staffer said they lacked color from the commercial food vs a wild diet. Not sure how credible the guy was. Also, that part of the aquarium didn't get sunlight.
The five RES I have in my aquarium also have washed out colors when my aquarium light is on, they are much darker and more colorful when the aquarium light has been turned off. They also show a very strong preference for hanging out in the darkest available part of my aquarium. Right now I have 3 out 4 of my aquarium lights shut off and have only been keeping one end of the tank lit up.
My working hypothesis is that RES have extremely light sensitive eyesite, more like walleye, which is why they get a washed out appearence under very normal lighting conditions. I also believe it is the primary reason they do not pellet train easily and why they hang out in deep water during the day.
