Over the last few years, more and more women have been experimenting with rainbow hair colors, eschewing their safe buttery blonds and caramels in favor of blues, greens, pinks, and purples. They've been trying to capture that trendy ocean-inspired mermaid hair, a look that feels daring without being "punk rock."

However, for those with a hair color that's anything other than light blond (which is most of the population), it's been impossible to get that look without bleaching their hair to oblivion and then adding the bold colors back in, a multistep process that can be brutal on locks. Then oil slick hair came along.

What is oil slick hair?

 

A post shared by Alisha Maldonado (@colorlove_byalisha) on Oct 6, 2016 at 6:09am PDT

This dyeing technique, also called oil spill hair, replicates the iridescent cool-toned colors that shimmer on a puddle of oil. Colorists use it as a way to give dark-haired clients their own version of fantasy hair.

Alisha Maldonado, a Redken colorist and the stylist behind Color Love by Alisha, says it's a popular trend because "it takes vivid shades to the next level. It's ... a perfect fit for those guests willing to step out of the box and do something new and fun."

How does a stylist create it?

 

A post shared by Alisha Maldonado (@colorlove_byalisha) on Oct 15, 2016 at 8:47am PDT

To create the look, Alisha first applies lightener to lift the client's dark hair color. "Unless the guest is already on the light blond side, a client's hair will have to be lifted to a pale blond shade to create a brighter effect," she says, explaining that the colors need to go on top of light hair if you want them to really show up. However, she doesn't have to completely bleach the hair to achieve that effect, so the hair stays relatively healthy.

Next, she pre-tones the hair to "even the palette and cool the warm tones out of the hair." Then she applies the cool-toned colors. She might reach for Redken City Beats colors such as East Village Violet, Brooklyn Blue, High Line Green, Time Square Teal, and Midtown Magenta.

She alternates the colors, applying a few shades to each section to "create a melt of tones and achieve the oil slick effect." When rinsed and dried, the hair still looks dark overall, but it has subtle washes of color that look particularly mesmerizing in the light.

How much does oil slick hair cost?

 

A post shared by Alisha Maldonado (@colorlove_byalisha) on Oct 15, 2016 at 8:46am PDT

It all depends on the type of hair you have and the market you're in. Alisha, who's based in a suburb outside of Chicago, typically charges $200–$250 for oil slick color for the entire head and $175–$190 for a partial area. Because oil slick hair requires multiple steps, it will cost more than a traditional color service.

What is the upkeep like?

 

A post shared by Alisha Maldonado (@colorlove_byalisha) on Oct 6, 2016 at 6:20am PDT

Though bright colors tend to fade more quickly than classic blonde and brunette shades, oil slick hair should still stick around for a few months. Pastel shades, on the other hand, tend to fade after a couple weeks. To help your hair color last longer, try to avoid washing it every day. Our "Eight Hairstyles for Dirty Hair That Can be Done in Five Minutes" article can get you through those potentially awkward no-shower days.

Which salons can do oil slick hair?

Alisha may work in a densely populated Chicago suburb, but pretty much any color specialist should be able to re-create this look for you. Years ago, smaller salons may not have had all of the fun colors, but nowadays, plenty of people want less traditional looks. To make sure your stylist knows exactly what you're going for, bring in a picture.