the only problem is when i tried it, it wouldnt stay in my hands and it was kind of expensive buying like 3 packs of food coloring. when i squirted red dye in my hand it fell on the ground and my mom though i was bleeding to death.
my friend and i used koolaid to dye her bunny blue when we gave him a bath.. it worked kinda okay, it turned his roots bright blue but he was still white on the outside..so it left him kind of tinted blue unless you ran your fingers through his fur then you could see the blue. though it lasted for AGES! might be worth a shot on some bleached hair..
I used kool-aid once.. Red. And I was running a marathon and started sweating and it dripped down my face and was really uncomfortable.
Use like.. not food coloring haha