They can do their color change at pretty much anytime. I think in the wild they do it in their first year or two, they will at least begin to change from birth on. They generally start with a little more orange coloration, and then it turns more yellow, then the dots will migrate. It can take years and years if your conditions are not right, or it may never happen at all. Most likely, you will see the dots starting to migrate towards his stomach in the next few months, more of a gradual clearing near the middle of his body.