I recommend looking at NYX cosmetics for purple eyeshadow, well pretty much any "crazy" or normal color. The purple shade I used for my Drocell was really vibrant and stayed put all day long with primer. Purple or Luxor would work well for your character. NYX can be found at Ulta and some other chain stores.
http://www.nyxcosmetics.com/p-2-single-eye-shadow.aspx