Alright Green and yellow leave blue and black and pink. If anyone wants to know why red is taken it is because the red ranger is still active so to speak and hasn't given up his morpher. The technical side is because the dragonzord megazord needs less zords to make and we can start without the pink ranger if need be.

Edit: The above answers the question of Rin's. Red is completely unavailable. If you want you're free to recolor any of the suits. I don't see why I needed to answer this twice it's in the rules above.