Hally Dark Mode Black Hair Colour Costume: Shego, Cruella de Vil If you have light or brown hair and your costume calls for a jet black colour, the Hally Dark Mode Black Hair Colour ($25) uses an ammonia-free, foam formula to gently colour your hair in just 30 minutes. Image Source: Everett Collection Hally Dark Mode Black Hair Colour $25 from hallyhair.com Buy Now