Mine got his full colors at around 14 months but he is still looking better all the time. I have pics of the progress of my male and female over the last year at the link below. I got them both at 6 months.
Mine started to colour up at around 10 months and colour up beautifully, especially when in natural sunlight/outside......before that he went through a very dull grey/light steel grey blue stage for around 3 months and would only fire up into dull blues, greens and murky reds when he was angry. He got into his full glory around 12 - 15 months and just glows pastel limes, blues, oranges and reds now
They all come into their own colours in their own time....I have seen some beautiful colourful chams at 6 months younger/older and and others take longer and their own sweet time. They are all beautiful
My 3 rescues were fully grown so I cant comment on their colour development.
Get A male from screameleons! vincent has awesome chams my boy is looking great at 9months.he does not compromise and has all the answers yo your questions..