SF P60L turns blue as batteries run down

Anyone else notice their SF P60L tint shifting to blue or purple as the batteries run down a little? I have hand picked my P60L out of literally dozens that have passed through my hands since the P60L was released. I picked it due to its pure neutral tint and nice smooth beam. After only three sets of batteries run through my C3 I noticed a blue tint out of the P60L. I changed batteries and now its back to its "normal" neutral. If others have noticed this maybe its normal. If not, maybe its just a defective module...?