The yellow stripes on my Maroon are very dark compared to others I've seen. I've had him for a couple of years now and I don't recall them ever being bright yellow. He has a anenome that I feed about once a week or so. Could it be that the anenome has a more potent sting in order to capture more food? I feed the fish a variety of dried flake, pellets, and frozen foods a couple of times a day.