How old is your Cham? I'm guessing the person you bought him from didn't know or tell you the locale. Try posting an updated pic and we might be able to help.
But fwit, no one can know for sure unless we know the lineage info. He might be pure or a cross but no one can know for sure except for the breeder.
Probably it's about 5 to 6 months old , he tends to turn into different colors last day I saw kind of yellowish and some red , also I have seen it turning to a clear blue and sometimes a a kind I green color as shown on the pictures .