They can change their eye color with their pattern and skin color. Yours is also not comfortable as he's sitting against the background using his camo pattern.
But he looks a bit skinny and his eyes also appear kind of cloudy, so I'd try to feed him heavily and keep a watch on him.
This is what rock bass should look like around his size. Either the one in front, or back. Not slim and elongated. They should be circular, or somewhat oval but with a fat belly. It's imperative that they're fed daily at that size.
I'm not criticizing you btw, as you said you received him from someone else. Just trying to give advice.