It's cutscene dependent. Sometimes her hair is Blue (See Apocalypse Nigh). Sometimes it's Light grey (Feared one) Here it's Boarderline Blue/Purple (depnds where you click). The FFXI Lighting system doesn't do her any favors. But in Dissidia 012. It's certainly lilac.
That being said. Deuteranopia is totally a viable option here too. She could legit be colourblind. *nods*