Man that is not normal bag seed then. You more than likely got some quality seeds from someone that grew good genetic plants and let them fertalize outside or maybe inside.

You need to take some pics and start a grow log, we are all interested in this. I can't give an exact strain name since there are many differant strains that do that, but I have grown Purple Power before and its pistols had a purple inverted v down the center of every pistol. Then the buds turned purple when they ripened.

JG