Mages in Lyrical Nanoha all have a predetermined color that their magic takes when they cast spells.
Note that these are the definitions given in the toys' universe and they play no role whatsoever in the anime, where the Jewelpets' powers are given more freedom. Magical Red can manipulate fire, Magical Blue can manipulate water and move objects, Magical Green can manipulate plants and use transformation magic, and Magical Black specializes in fortune-telling and the occult. There is also White and Black, magic which are only very rarely encountered.
Magical Girl names indicate by color which area one has mastered.
INVADERS of the ROKUJYOUMA!?: There are seven common domains of magic named and colored for the standard rainbow.
