This Just-Launched Hair Mask Kept Emma Stone's "Chocolate Copper" Hair Glossy in Cannes

It's no secret that Emma Stone is a hair-color chameleon. She may be well-known for her fiery red locks, but the actress is actually a natural blonde. She's also gone platinum, strawberry blonde, copper, and most recently, a rich espresso shade.

As anyone with color-treated hair knows, your strands can take a beating from switching up hues (especially when you opt for something more drastic like platinum), so it's worth having an arsenal of buttery masks, bond-building treatments, and repairing serums on hand to keep the hair luscious and vibrant.

For the 2024 Cannes Film Festival, Stone happened to use a brand-new formula from her longtime hairstylist, Mara Roszak, whose brand, Rōz, has a cult following for its mane-enhancing haircare and styling products. (Its Willow Glen Treatment Oil is a special winner among WWW editors!) Ahead, find all the details on the launch and how it has kept Stone's locks soft and shiny.

Today, the brand has dropped its new Foundation Mask, a thicker conditioning formula for extra hydration and repair. FWIW, I adore all of Rōz's offerings, but if I had to pick, I'd say the Foundation Shampoo and Conditioner have been my ultimate favorites; the shampoo is gentle yet effectively refreshes my scalp, and the conditioner is lightweight yet buttery enough to deeply hydrate my thick-yet-fine, 2c mane. Plus, they smell incredible! I test loads of shampoos and conditioners given my job, but I reach for Rōz when my hair really needs some TLC. I know it just works.

Considering this new mask is an extension of the Foundation range, I have a strong hunch I'll be obsessed. I typically use hair masks in place of conditioner anyway (since I only wash it two to three times a week), and I've been patiently waiting for Rōz to offer a richer confection. Consider my wish granted.

Roszak has been testing the new launch on Stone (as she has with a few of her products, such as the Air Thickening Spray) for a few months now, most notably before the star hit the red carpet during Cannes. There, Stone sported chocolate-copper hair color made even more vibrant by the mask's proprietary BotaniComplex. The special ingredient helps preserve hair color (in addition to reducing breakage and improving elasticity), which only enhanced her soft, mermaid waves as she floated down the carpet. Stone recently debuted a deeper espresso shade (styled by Roszak!) at the Kinds of Kindness premiere this past June, and I can't help but wonder if the mask is similarly responsible for its glossy, "liquid" shine. After all, once you fall in love with a Rōz product, you seldom set it aside until the very last drop.

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