Size is Race/locality dependant, but males max out normally around 4' females can hit 6'...
I keep males in a 2x2x2 as adults and females in a 3x2x2. The only way to know 100% a specimen will have a high blue content is to buy it as a adult...
but the more blue you go the higher the price tag... i could sell all my fish (asian aros included) and still not afford this specimen: