New in crayfish keeping:)

HI all, im new in crayfish keeping. And i have a few questions.
1) Crayfish of opposite gender will confirm not fight?
2) Can crayfish of different colour breed?( e.g white +blue?)
3) Can crayfish with different colour be put together?
4) Is there a forum is specially for crayfish?( If not, can give me some useful websites on crayfish)

thank you in advance