This can occur especially in balayage or ombre hair, or if the hair has been dyed multiple times before. Well, over time, lightened sections of brunette hair can turn brassy and the colour fades. Or if you use a purple shampoo, you can't use toner anymore. Purple shampoo on brunette hair with highlights, or coloured hair, can be a very effective toner. Ahead, everything you need to know about how to use purple shampoo.. What is purple shampoo good for? Purple is opposite orange on the color wheel, so the purple color cancels out the brassy yellows and oranges in hair and brings the natural hair color back. If you use them correctly, the two products can complement each other. How do purple shampoos counteract the yellow in gray hair? Most things in life aren't black and white. Using a purple toning shampoo is a key step in keeping your hair color looking fresh, vibrant, and like you just left the salon. To get why the tinted product is so crucial to hair color maintenance, you first have to understand brassiness. Also, if you're wondering about your dark brunette or black hair, to combat the same issue I recommend using a blue shampoo. It's not like if you use a toner, you can't use a purple shampoo. Purple shampoo works a bit like a corrector for your hair, in the same way that peach tones combat the appearance of dark circles under your eyes. Make sure you do a test strand first to see how porous your hair is and how well it reacts to the shampoo! How to use purple shampoo and toner together. What effect will purple shampoo have on brown hair? Whether it’s blonde, brown, or gray. all color can get brassy but not all hair colors react the same way to purple shampoos. The colour that is opposite to yellow in the colour wheel is purple, so this is the colour to use if you want to counter the yellowish tones on your hair. How?