too many to list, think there are 12 colors now plus the 3 greens, and 5 patterns, and spaldings, combine all those up, there are near 200 combos you can get
also the java, burmese, and imperator greens (all individual subspecies)
patterns can be a combo of any of the above pretty much, cant be bar wing and black shoulder though, will be one or the other there.
Then on top of all those, add in spaldings to all of them.
Think the recent total is about 185 possible colors/patterns, with about 100 or so already exsisting.
Brad Legg and Sid Drenth have the 2 best websites to show all of these
If I were to purchase a trio that I've been looking at (white pair + blue hen) what color variation could I expect from the white/blue breeding? Is there any chance of getting a blue or silver pied or what would I have to breed together get that ?
No to get a pied you need a dark pied, or a pied then you can breed that to a white and get pieds but you can't get pieds from just breeding a India blue to a white. When you breed an India Blue to a white, you will end up with a split to white which looks like this: http://database.amyspeacockparadise.com/whiteprimaries.JPG
Notice the wing feathers of the bird are white but the whole bird is not white. Blue is the dominant gene so it shows up more than the white. If you breed a split to white with a white, you will get white peachicks and if you breed two split to whites I think you will get all white chicks also because they carry the white gene.