Octarine

[…] colors like octarine, the eighth color, an elusive spectral mix that's hard to describe and impossible to perceive. That's the thing about color. Try describing a rainbow or a sunset to a blind person or ask a synesthete[…]

Source: wiktionary

Back in ScienceFictionaLand, octarine is the color of magic, an animating force in the Discworld series by Terry Pratchett. A fluorescent, greenish-yellow purple, octarine can only be detected by wizards and cats.

Source: wiktionary

Another way of looking at the magical character customization option [in which players choose their color] is that it allows players to find their own octarine, the color of their own magical self in Peter Carroll's vision of things. Octarine is a fictitious eighth color of magic invented by Terry Prachett in his novel The Colour of Magic and later used by occultist Peter Carroll in Liber Kaos to describe the color of a magician's rebellious, mischievous sorcerous self[…]

Source: wiktionary

Octarine, the color of magic, glows from your finished pages.

Source: wiktionary