6 months? I think I got him in January. When I first brought him home he was mostly white with a greenish blue sheen. Then the dark blue 'speckles' started showing up here and there. Then the red appeared in his dorsal and his ventral. That disappeared and he started getting very dark blue streaks in his finnage. Now that's going away too and he's going back to a white/light blue. Just in the last 6 hours his beard has gone from black with a few white spots to white with a few pale black streaks. He's literally changing before my eyes. He's also hiding in a plant cause I won't stop staring at him. :P
Here's a pic with the red in his dorsal from a while back and you can see where the dark blue streaks were coming in strong and then there's a pic from tonight, where you can see they're almost gone. I don't know anything about fishy genetics or color changing. It's neat to watch though.