Blondes, highlighted hair, and grey or silver hair that needs custom toning. It is especially useful if you like your current Paul Mitchell shampoo or conditioner and only want to add toning power, or if your hair needs a different strength of toning from week to week.

Brassiness is not the same every week, so a fixed-strength purple shampoo is not always right. Toning drops let you decide each time how much violet goes into your routine, and because they mix into conditioners, treatments and stylers as well as shampoo, you can choose where in your routine the toning happens.

Add to your favourite Paul Mitchell shampoo, conditioner, treatment or styler in the palm of your hand. Use several pumps, until you reach the desired level of toning. Mix well and apply to clean, damp hair. Wash hands immediately after use.

Pros:

• Fully customizable toning strength
• Turns products you already own into toning products
• A few pumps per use, so a small bottle lasts
• Vegan

Cons:

• Concentrated pigment: the brand advises washing hands immediately after use
• Strength depends on how many pumps you add, so it takes a little trial to get the tone right
• Made to be mixed into Paul Mitchell products (per brand directions)