Yeeeeh, maybe that would have done it. My rationale was 'Spell is hotter at the hand thus brighter, and tapering out towards the end of the trail.' Maybe I'll fiddle with it some more.
Very cool! I like it .. the flesh and head came out well esp ... You're right, the magic bits aren't quite right somehow. I guess I would have left the yellow bits only in the deepest recesses and allowed more green to dominate - especially in the projectile head part