So, next time you're in the middle of a hair disaster, consider grabbing a purple shampoo before you start to panic. But remember that purple shampoo is meant to be a temporary fix until your next dye appointment—not a permanent panacea. He advises using a shampoo with a violet or purple tint to keep gray hair color vibrant and fresh. "It doesn't need to be a daily wash, but using it once a week will cut brassiness and give you spectacular shine." Avoid using any shampoos that add warmth to gray hair, as cool-toned shampoos will help hair better reflect light. Since gray hair tends to be drier and prone to frizz, Dueñas also recommends avoiding harsh shampoos, as "it's important to leave as much moisture in the hair as possible." Purple shampoos cancel out unwanted yellow tones in the hair,” says Bodt. If you’re a faux-blonde looking for upkeep, purple shampoos are an essential investment. “For blondes who are looking for more neutral, cooler, or ashier tones, purple shampoos can help offset the warmer tones that appear in blonde hair over time,” adds Lynch. We used the purple shampoo twice a week and found that it kept our honey blonde highlights looking creamy and cool – even two months post colour. It lathered well in the hair, smelt refreshing and didn’t feel drying once rinsed, although we’d still recommend following up with a nourishing conditioner to pamper our hair and seal the hair cuticle. Top tip: we massaged the foaming shampoo into our hair for two minutes to make sure each strand was properly coated. As with any shampoo, you want to look for a high-quality one that is sulfate free," he says. "A good rule of thumb is that the lighter it is, the more subtle of a tone it’s going to be. The brighter the purple, the more drastic the results will be."

The more you use purple shampoo, the more it makes your blonde look dull, because you are continuously depositing color shampoo," Kelly points out. So, while it's important to keep a bottle on hand, that doesn't mean you can eschew your hair appointments altogether. What To Look For in Purple Shampoo When it comes to hair, there’s nothing better than fresh color. The challenge? Maintaining that just-left-the-salon level luster until your next dye job. Blondes in particular may notice signs of brassiness over time. This yellow or orange cast can be caused by a number of things, including "your color oxidizing over time, exposure to UV light, chlorine and even traces of copper in your water,” explains Meri Kate O’Connor, celebrity colorist at Loft 647 in West Hollywood, California. This is where a purple toning shampoo can help. What is purple shampoo good for and what happens when you use it?The merits of a purple wash extend further. “I like to use them when I’m shampooing a wig and I want to get rid of brassy tones and keep the color cool and fresh,” says Los Angeles–based hair stylist Davontae Washington, who works with model Winnie Harlow and singer-songwriter Kali Uchis. And to double down on that freshness, a pro-level hydrating mask can help restore strength and moisture in overworked strands. “My favorite product in the world is K-18 Leave-In Molecular Repair hair mask,” says bicoastal colorist Aura Friedman, responsible for self-described “iconic looks” on Lady Gaga and model Soo Joo Park. She recommends using the mask on clean, damp hair and leaving it to soak in for several minutes; that allows time for the “biomimetic [ingredients] that replicate hair keratin” to hold onto color molecules and replicate the look of so-called virgin hair. This shampoo is marketed for people with blonde, gray, and highlighted hair, and boasts a strong color-depositing formula. Indeed, multiple reviewers write about how impressed they are with it, saying that they noticed a marked improvement in their hair color after just one wash. Because it’s so highly pigmented, the brand recommends using gloves when applying this shampoo to wet hair before lathering well and rinsing as thoroughly as possible. If you find that your hair is in even more need of anti-brassy TLC, repeat the process and leave the formula on for three to five minutes before rinsing. If you’re adding a purple shampoo to your regimen, start by using it once a week and only build up if needed. Remember that while purple shampoo is a beneficial tool in keeping color fresh, it’s important not to go overboard. “If you start to notice too much or an overload of purple tone in your hair, put the purple shampoo down,” he says. “Opt for a clarifying shampoo to remove the tone and keep your purple shampoo routine to once a week or less. Alternate using it with color-safe shampoos—or mix them together for less violet deposit.” How do you choose the right purple shampoo formula for your hair? How often you should use a purple depends on a few factors, including how frequently you shampoo your hair, how brassy it is, and how well your hair holds tone. If you’re just starting to see minor brassiness now, use a purple shampoo once a week. Still unsure of where to start? Don't worry—we've got you covered. Below, the best purple shampoos to keep your shade of blonde hair bright. The Best Purple Shampoos

Redken’s Color Extend treatment shampoo is enriched with a deep violet pigment that’s extremely effective at cooling warm undertones and counteracting yellow tones. As well as working wonders to clean up dull blonde shades, the hydrating shampoo uses a Triple Acid Protein complex to strengthen the hair cuticle and nourish each strand. These fortifying proteins hydrate and protect each strand to prevent the damage that’s a common side effect of bleaching and toning hair. This is a strong colour-correcting shampoo, so we recommend wearing gloves while massaging it into hair to prevent staining on the hands. You’ll only need to leave it in the hair for a few minutes. For an extra blonde-boosting benefit, follow with the conditioner and conditioning treatment mask in the same range. To keep hair looking its blonde best between salon visits, minimise washing and rinsing it to avoid dumping your toner straight down the drain. Also try washing in cooler water to avoid stripping colour out of dyed hair. When not washing with purple shampoo, be sure to use a shampoo for colour-treated hair as this will protect the colour molecules intact. Blonde hair can turn yellow with time for two reasons. The first is salon-applied toner rinsing out over time to reveal a yellow undertone. The second is the hair shaft absorbing minerals and chemicals from the environment, which can cause yellowness. Chlorine from swimming pools and even sunlight can be major culprits for introducing yellow tones to blonde hair. This is particularly true of bleached hair, which is more porous. The violet tones in purple shampoo counteract any brassy tones in the hair, giving a more silvery finish that appears brighter and more vibrant. Color shampoos can even work on brunettes but if you want to cancel orange tones which typically happen on brunettes you might want to try a blue shampoo,” says Bodt. Hairstylist Kevin Kelly adds that purple shampoo is only really a good fit for people with light hair. "You cannot use purple shampoo on caramel highlights," he says. "It will not do anything. It’s not light enough for the color to grab on to." He also adds that purple shampoo works wonders "if your hair isn’t light enough or your hair was highlighted or colors in properly."Come summer, bottle blondes know the importance of preserving hair color at home. This is where the best purple shampoo for your hair, whether it’s a traditional cleanser or a deep conditioning treatment, comes into the equation. “Blondes have more fun, but the fun doesn’t last long!” jokes colorist Richy Kandasamy. “Blondes have a very light palette—and delicate, clean blonde color tends to fade faster, lose shine, and can look brassy or yellow very fast.” Below, find a breakdown of how purple shampoos work to keep hair color bright and vivid, as well as how best to work them into your routine. What is a purple shampoo?