I bought the blue one. It was my first time bleaching and dyeing my hair blue, so I bought it to have a little fun. I'd heard that blue tends to fade easily, so after the second shampoo, I've been mixing this with my regular shampoo in a 1:2 ratio every two days. I'm afraid of splashes getting on the walls and floors, so I won't use it alone... and it's best to wear gloves too. It doesn't lather well, so I recommend mixing it in with other products. It can't be used for dyeing, but if you want a darker, longer-lasting color, apply it once to your hair before wetting it, leave it, then mix with shampoo. It gives you the effect you're expecting: "Oh, my hair is dyed today."