User blog comment:Lightning the Skrill/Night Fury's Plasma Blast; Blue or Violet?/@comment-28891334-20150324203123

It is mostly a Blue/Violet glow produced the De-excitation of the already excited components of Air, or rather the major components of air, Nitrogen gas (N2) and Oxygen gas (02). Nitrogen gas Produces a vibrant violet colour while Oxygen produces a dull blue/white colour, thus forming the Violet/Blue/white appearance of Nightfury's and Skrill's unique shots.