Blue vs. Purple Shampoo: How to Choose

As lighter hair loses pigment through the chemical process of lightning, it tends to lift yellow, where darker hair loses pigment and lifts orange. But the undertones that appear in your hair will help you determine whether you should try blue vs. purple shampoo. If you have brassy orange or even red tones, blue shampoo is your best bet. However, blue pigment won’t help with yellow undertones. The reverse is true for yellow undertones. Purple shampoo is great for removing yellowness, but not effective for orange or red tones. While you should stick with purple or blue shampoo most of the time, you do have the option to use both if you have multiple undertones. But a good rule of thumb is that a blue shampoo is best for dark hair and brunettes; and purple shampoo is better for blondes, silver or gray hair.

A blue or purple shampoo won't fully replace your everyday shampoo. You’ll swap it in every few washes. How often you do is entirely up to you. We recommend starting with once every week or two, then building up as needed. Always use blue or purple shampoo on wet hair. Don’t apply it on dry because the hair is more porous and it will grab too much of the blue or purple pigment. Lather it up in your hands and work it into your scalp, using gentle circular motions work the shampoo between strands, and down the shaft. Leave it on for two to four minutes depending on the amount of brassiness in the hair, and use cool water when rinsing, to close the cuticle and seal the color. Always follow with a conditioner for colored hair. If you start to notice a purple or blue tone in your hair, you’re using it too often. Opt for a clarifying shampoo to remove the tone and keep your blue or purple shampoo routine to once a week or less.