Blessings of the Spectrum

I guess I'm late to the OC October LOL.
I am still trying to come up with a proper backstory for this girl, but it goes along the line of a gray magic user who tattooed runes all over her body (with invisible inks). Allowing her to cast spells almost instantaneously and without the need to construct magic circles. The illust depict her casting the spell of "Blessings of the spectrum" which is simply the complete manipulation of colour and thus light.
^something like this, I guess LOL