If they are partially green -- they are not ripe yet. You might want to find out the name of your poms so that you can do some research on them. Just calling them a Russian variety doesn't help much. I have Wonderful and Angel Red poms and don't go by uniform color or sound when harvesting. They are ripe when there is no more green and the skin is taut like leather. The longer you let them sit on the tree without splitting, the better they will be. Harvest right away if they start to split.

Here is a link that might be useful: Pomegranate Tour

Thanks, that is helpful. I knew there weren't ripe yet, but I also wondered whether the uneven color meant that they was something else amiss.