This is incredibly interesting--and mystifying. A cider-maker in Pennsylvania, Alan Yelvington, ran an experiment. He pressed a batch of apples, separated the juice into seven small carboys and pitched each with a different yeast strain. Yeast plays a large role in the flavor profile in cider--that much is not surprising. But what is surprising is what happened to the color of the cider. Have a look.
Raise your hand if this makes any sense to you. I'll poke around and see what I can turn up on why yeast would affect color and report back if I find anything.