Defiantly mix unknown birds together in a totally unknown pen to anyone being mixed together. Anything else you can throw at them to confuse them helps too. I know it's hard when you first start out, because pen space is tight or even non-existent, but breaking up their sameness actuality causes them to bond quicker. If someone just suddenly showed up in your house, you would probably peck their eyes out too. If you and an unknown person found yourselves together in a totally strange place together, then you would bond better too!
I defer to quaillady as to what colors one gets, because I haven't gone down this particular road just yet.
I will say this, that crossing range pattern birds with wild pattern birds (range trumps wild) but it does create a more pleasing range pattern IMHO.