GUILT-FREE GLAMOUR!® Siren's Song is a neon blue-green hair dye that glows under blacklight. For best results, we recommend applying to hair that has been pre-lightened to the lightest level 10 blonde. * Style: Classic Semi-Permanent Hair Dye * Color: Siren's Song * Color Description -  Cool Neon Blue Green Hair Dye * Volume: 4oz / 118ml * Ingredients: Vegan Friendly, PPD Free! * Additional Features: Benefits of Conditioning Hair, Resealable Tub For Longer Use, Comes With Instructions, Glows Under Black Light in the Dark * Duration: 4 - 6 weeks * For Best Results: See Instructions Tab  Tested on celebrities, not animals™.