Yes, it's sharpie dye that has been unsuccessful for people in the past. RIT is the go to choice and I think FW ink will also work, but perhaps only with the airbrush method.
See me at Vancouver's own Anime Revolution in August 2012!
See me there as Lumpy Space Princess.
Princess Bubblegum-Adventure Time
The Flower Card-Cardcaptor Sakura
Rika Furude(school outfit)-Higurashi No Naku Koro Ni