Not very effective. I have dark strawberry blonde hair, and used the Chocolate Kiss color. It barely made a difference in my hair, and i used alot. It did make my hair a little shinier, though. Rubs off on pillows overnight... It is inefficient, as it washes out, but according to the website, it is intended to cover gray hairs. If you are going to use it for that purpose, something that lasts more than a day would be better. Also extremely runny and messy, but doesn't stain hands.