I caught one about a month ago in a cray fish trap. Yesterday I noticed something about it I never would have guessed... It can control the darkness of its stripe and spots!!! The stripe on its side, darkness of the fins and spots on its "back" can go from very dark almost black to being a barely visible yellow the same color as the rest of its body (which also gets a bit lighter in color) in a matter of seconds. I was just about to start a thread about it but saw your thread and fish that looks to be about the same size as mine...
Took me a month to notice =) Seems that when its "happy" or being aggressive chasing feeders its stripe will be extremely dark but when this other sunfish in the tank with it (and about the same size at 3") chases it around the tank it will turn yellow so that to me it looks like a different fish! I will try to capture some pics of it both with and without its stripe its really impressive to me =P