Earlier this week, 26-year-old Zosia Mamet, known for her portrayal of the speedy-sputtering Shoshanna on HBO’s hit series Girls and currently promoting the upcoming A Most Violent Year, showed up at a press junket sporting a new look that had paparazzi and trend-watchers alike look twice: a newly minted choppy bob of "antique gray" hair.

It would have raised more eyebrows had Mamet not been the latest in a stream of young celebrities experimenting with gray: Kylie Jenner tipped her raven mane with gray, and both Orange Is the New Black's Dascha Polanco and hair chameleon Rihanna have stepped out onto the red carpet with unicorn-like gray ponytails.

Gray hair's closest predecessor was platinum hair, which slowly morphed into a darker iteration. In the aughts, gray was sneered at as the province of British hipsters, but it still managed to make its way, sporadically, to the covers of high-fashion magazines.

Four years ago, Tavi Gevinson was still blogging from Oak Park, Illinois, as the bespectacled Style Rookie, her pageboy locks a washed out slate blue-gray. More recently, Nicole Richie, Lady Gaga, and Pink, and Kelly Osbourne have followed suit.

Gray has, classically, been associated with monotony. The dictionary offers a dank picture of the emotions evoked by the color: “cloudy, overcast, dull, sunless, gloomy, dreary, somber, bleak, and murky” in terms of weather; “ashen, wan, pale, pasty, pallid, colorless, bloodless, white, waxen” for images related to age; and “colorless, nondescript, insipid, jejune, unremarkable, flat, bland, dry, stale,” for a subdefinition of “without interest or character.”

For all the color's blahness, it’s seeing an unexpected rise in popularity among the Millennial Instagram set. Gray has found a resurgence as a shade that is both natural and supernatural, with Pinterest pages celebrating the rainbow of women, grinning and gray, as “hot.” Sometimes the color is referred to as “silver,” along with “Arctic” or “icy,” for understandable reasons. Gray connotes dull, elderly, and boring, but silver is magical, sophisticated, and chic. Grandmas have gray hair; starlets have silver hair.

In practice, the color exists on a spectrum. “If you picture someone with salt-and-pepper hair, the salt is more the silver, and the pepper is more of a gray,” said Susan Hurley, color director with Chicago’s Art and Science salons. “[Silver is] a lighter gray. More people prefer the silver versus the gray, but not by much.”

Hurley has been in the hair color business for 20 years, 15 of those as colorist. She grew up in a family whose members grayed quickly, in their 20s—and celebrated it. Gray, for the 34-year-old brunette, is “avante garde, a classic sort of feel.”

“Women and men gravitate towards cooler colored hair; gold is not friendly for an average client,” Hurley said, referring to the color wheel that informs much of her day-to-day work in matching complexions with hair color.

Despite its ubiquity in older people of all ethnicities, gray is quite the dye job to have and maintain. Gray’s artificial sister silver is also surprisingly nitpicky with respect to hair tone and complexion.

“Very few people can achieve it,” Hurley said of the now-glamorous storm-cloud shade. "The actual gray hair you see on Helen Mirren can’t be [recreated], but if you want that more bold Gwen Stefani steel feel, that is something only a small population can achieve.”

To do so, a stylist needs to strip all the pigment out of the hair; it's especially difficult to do so on darker hair with red and gold pigment. The pre-bleaching routine dries out hair and can weaken it. Gray’s lightness means that it washes out easily, which means toners and vigilance are necessary.

The finickiness of a silver/gray hair-dye job is intriguing for a color that is so often associated with being slack and boring, the type of hair one presents to the world when one does not care a bit about appearance anymore. So why are many twenty-something starlets indulging in the granny chic shade?

It can be tempting to declare it as a feminist commentary. Men are considered distinguished and sophisticated with flecks of gray or a shield of silver. George Clooney, Anderson Cooper, and John Slattery stand atop a pedestal of graying beautifully, aging into the dashing gentleman, the “silver fox.”

But women cannot attain silver foxdom (vixen-dom?) in quite the same way. Sure, every once in a while, you’ll read about Helen Mirren’s “stunning” style. And singular stripes of charcoal, like Indira Gandhi’s or 101 Dalmations’ Cruella de Vil, often evoke power, or even a corresponding streak of evil. But there's no dominant "hot" stereotype for the female gray-haired woman, despite a minor "pro-age" movement to embrace one's natural beauty past middle age (see: 60-year-old model Cindy Joseph).

Pop culture depicts gray-haired ladies as harsh or badass, often with an undertone of masculinity. Julianne Moore’s recently adopted gray for her take on the severe President Coin in last The Hunger Games films; in the books her hair was described as “the color of slush that you wish would melt away.” X-Men’s Storm was a literal representation of the fury of thundershowers, making her shock of gray hair electrifying and appropriate. Game of Throne’s Daenerys Targaryen, freer of slaves and Mother of Dragons, has platinum hair that's described as silver in the books.

The influence of visual culture aside, going gray may just be another contrarian thing to do, a fashion statement. The unconventional dye job is just another path to be different in a way that doesn’t involve the permanence of tattoos and piercings (think of the way pixie cuts have also challenged gender norms). But being young and gray offers an unexpected juxtaposition, a way to be both fresh and jaded. When asked why she dyed her hair, Mamet said she was just bored. What better, completely traditional color to signal the fatigue of youth than gray?