bearded dragon colours?

I bought a beardie in late October, he's now about 4 or 5 inches long in the body.

I think they are beautiful creatures, he's just shed for the first time and it's cool to see his colours changing.

Day by day, he seems to be getting more vibrant red lines along the sides of his mouth and round his ears. His back is a light peppermint green kinda colour, with light red and dark brown areas.

I know these are pretty standard colours, they're all good! Morphs are great but I love the more natural colours as well.

Anyway, my question: at roughly what age do beardies achieve their final adult colours? Thanks for your answers