or single process (lightening or bleaching, if needed, followed by the actual pigment). When you are in between salon visits, there are various professional and at-home options to help maintain a healthy-looking color. Exhibit A: Hair toner. It does exactly what it sounds like—tones your color to control brassiness and keep hair looking healthy. Yet, there is still confusion on how it works.

That's why ELLE.com consulted a panel of expert colorists, including Kristin Ess, celebrity hairstylist and founder of Kristin Ess, IGK Miami colorist Savanna Palladino, and Jonathan Colombini, L’Oréal Paris style + color expert, Sharon Dorram, master colorist at Sharon Dorram Color at Sally Hershberger Salon, to break down everything you need to know bout toners and how they’re used.

What is a hair toner?

Hair toners can be used to achieve two things. “It can be used to add pigment to hair color that has faded over time and it can be used to counteract unwanted colors like yellow tones or brassiness. Toning and glossing also add a nice boost in shine to the hair,” Colombini says.

Ess describes toners as a “topcoat for your hair.” It usually comes in a gel or gloss-like formula and works to emphasize or deemphasize certain tones in your hair and add shine. Palladino adds that toners aren’t one specific product. You usually can’t go out and just buy a “toner.” Demi-permanent colors, glosses, tinted shampoos, and conditioners can all be considered toners because they all contain pigments that adjust the tone of your hair. Typically, the pigment delivered in toners can last about three to four weeks.

What are the different kinds of toners?

Demi-permanent colors, a.k.a. glosses, deposit color without lightening the hair. "Glosses typically last about six to eight weeks, and there is no grow-out process; they just fade out of the hair," Palladino says. Glosses work for clients who switch up their hair color more often or want to try something new without the commitment of permanent color.

Like the commonly-used purple shampoos and conditioners, purple and blue toning products work to eliminate brassiness. Purple toning products are perfect for blondes since the violet reduces yellow tones and eliminates brassiness to keep blonde hair looking fresh. In contrast, blue toning products are perfect for brunettes since the blue cancels out orange tones and increases luster in the hair.

Why do people need hair toner, and how is it used?

Ess says, “People need toning glosses for many reasons, but the most popular is to either maintain the tones in their hair that they love, or to adjust warm or cool tones.” Toners can also be used to add shine, increase the softness of hair, or reduce the appearance of split ends. Dorram adds that toners can bring life back into the hair that looks brassy or dull and make the existing color more vibrant.

What are some benefits of using a toner?

Toners are great multi-use products that have a variety of benefits. They, of course, refresh and enhance tone, but they also add dimension to hair color and eliminate discoloration. Toners also strengthen hair by creating a protective barrier around the strands and balancing the hair's porosity by filling in the shaft. Lastly, toners add volume and shine to the hair by plumping the hair cuticle to make it fuller, while also sealing down the cuticle to create reflection and shine.

Can you use a toner at home, or should you have it done by a professional?

“If you need any major colorwork, you should always go to a pro,” says Ess. “You can really mess up your color by going out of your ‘hair color family’ with any color product at home.” However, she also notes that you can definitely take care of toning at home, as long as you’re careful.

Colombini agrees that toners should be used carefully. Thanks to a bevy of user-friendly systems found in your favorite beauty stores, toning your hair at home has become more popular and more manageable. Colombini warns that toner should be applied to clean hair. “I prefer to apply to damp hair. This helps the product move evenly and easily through the hair,” he says.

Dorram advises adding a little shampoo to the toner to emulsify it throughout the hair, and notes that, if you follow the instructions, toner is safe to use at home. Just conduct a little patch test with a small hidden chunk of hair at the nape of your neck.

What are some products that can be used to tone your hair at home?

If you’re wondering what products can be used to tone your hair at home, Palladino recommends IGK’s Mixed Feelings Leave-In Blonde Toning Drops. The purple pigment drops mix in with any of your favorite hair care products like shampoos, conditioners, oils, creams, or stylers to create a toner.

Ess recommends the Signature Glosses from her eponymous line for at-home toning. Her glosses come in eight different shades, from clear to dark brown-black to help boost color-treated hair. She notes, “The Signature Glosses are safe to use at home because I have intentionally formulated them to be less powerful and less pigmented than what we use in the salon.”

My hair is currently an ashy gray-silver-blonde (my natural color is black), so I use Overtone’s Extreme Silver Complete System to maintain it. I haven’t had my hair colored at a salon in six months, but my gray hair is still going strong, thanks to these products. Overtone also has lines for several different color families—including blue, rose gold, purple, green, and more—in pastel, vibrant, and extreme ranges.

Colombini is a fan of L’Oréal Paris ‘Le Color Gloss’. "It’s a one-step, no mixing, color conditioner that enhances your color while boosting shine. Offered in 13 shades, you’ll be sure to find a color that is best suited for you," he says.