its not only ok to house juveniles single, it is really adviced to do so. they should be kept single until you can definitly be sexed. what is at the age from 6 to 10 months. so you can be totally sure you dont put 2 males into the same cage.
i havent head about any albino cresteds (nor do i think its adorable) and also havent heard about black and white cresteds. (but many have small black spots)