Doing a little digging, cant tell you who some of the other flags were, BUT can eliminate a few for you.
73rd PA got away with their Regimental
Loomis took a lot of fire, but didnt get close enough to have lost any of theirs. Also, Lightburn is also not a likely suspect.
Another thing to consider is what were being considered flags, some Union regiments had pretty elaborate Guidons that might have been mistaken as colors, so that one regiment had the potential to have 4 flags with the two guidons, a national color, and a regimental color.