User blog comment:CNBA3/Gajeel's Iron Dragon Magic/@comment-16344653-20130730022206/@comment-4829046-20130730045924

Oh I see. But what is your argument again? That would simply mean that the magic formed takes on a particular colour when the soul connects with Nature Energy. I see no problem there.

And since Erza has used the same colour since the very moment her magic awakened, the colour is probably permanent. But take Jellal for example. He uses both Darkness and Light but the Darkness was triggered by Ultear. So his original colour would most likely be his Celestial Body colour. So I suppose the colour of the innate magic is their main one. But this is confusing. I prefer mages that use only one type of magic, that way the colour is always the same.

So in the end, Gajeel's magical energy is green. End of story.