Without a before/after picture, it's hard to say what exactly you're noticing but the fish is definitely going through the color morph. While there's no set time on this, it can take several months to complete. Some don't make a complete transformation in captivity. How big is the fish? My blue face had almost complete adult colors at 4-5 inches. Usually after that, there are more subtle changes and a deepening of colors in certain areas. Thats a nice looking fish.