Possibly a very silly question but I'm going to go for it....

[Amer]

Is it so recessive that i would need a partridge hen to get partridge chicks or would it come through ok if a partridge rooster mated a different coloured bird?

Yes, you would need a partridge hen in order to produce more partridge.

 

[Willawong Hill]

Yes, you can have multiple pens with different colours in each if you're happy to do that set up and have a few roosters. You can go as big as you like! We all wish we could have more. Black and blue will be fine together along with splash, so that cuts the number of pens somewhat. Will be interesting to see if your white roo is hiding anything under his white. feel free to post pics of what you end up with!