Newbie Temp Dye help please!

Hiya,

I'm a really new cosplayer, it'll be my first time cosplaying at MCM London in October, really pumped!

I'm going as Gender-bent Stocking Anarchy from Panty and stocking, I've got my whole costume sorted but I'm really stressing about the hair as its probably the second most iconic thing about the character (The first being her stockings ). I REALLY hate wigs, they're itchy, uncomfortable and It'll end up ruined before MCM, knowing me. Because of this I was thinking of temporarily dying my hair.

I'm just looking for advice about temporarily dying hair, Any products that are especially good, the best way of going about something like this, tips and tricks that you may have picked up, or about cosplay in general as I think its all really cool and want to do it more and better.

My hair is naturally black and medium length, a little bit curly but I'm gonna straighten it. I was gonna dye it Dark purple with pink edging and streaks round the back.

Heres a pic of the character in case you don't know her, Im also open to suggestions so if you have an idea, let me know 

Any advice would be greatly appreciated and may even get a chance to thank you personally at MCM London! 

Thanks