“Grey” is the new green.

Universal’s controversial “Fifty Shades of Grey” movie is so hot that advertisers have whipped themselves into a frenzy — snapping up all the in-cinema airtime ahead of its release next month, one major ad seller said Tuesday.

The movie, starring Dakota Johnson and Jamie Dornan, bows Feb. 14 but advertisers that haven’t yet booked their ads in theaters — where moviegoing lovebirds are expected to pack multiplexes — are out of luck.

National CineMedia, which sells ads for the AMC, Regal and CineMark theater chains, is sold out for February, its president, Cliff Marks, told The Post.

The demand is fueled by “Grey” — based on the book about a college girl’s kinky relationship with a high-flying control freak.

It is the first time in years NCM sold out February, Marks said.

One February advertiser, European Wax Center, is building its current marketing effort around “Grey” and the Academy Awards.

The cinema advertising business is expecting a blockbuster year thanks to a slew of hot movies.

Three movies from the anticipated slate are expected to attract the most dollars, said Marks — “Star Wars,” the “Despicable Me” spinoff “Minions” and Pixar’s first release in some time, “Inside Out.”

NCM, which is trying to forge a merger with its rival Screenvision, reports that it is taking a wider portion of Madison Avenue’s video budgets as CPMs rise.

NCM has commitments for $225 million in ad revenue for the year, a jump on last year’s $110 million, Marks said.

Screenvision CEO Travis Reid told The Post: “We’ve had a lot of interest in ‘Grey’ … from a lot of female-focused brands. It’s the biggest female movie since ‘Sex in the City.’ ”

Marc Wallen, managing partner at MediaCom, told The Post that the “ad model has changed, and cinema is more affordable and in line with TV costs. It’s also more measurable.”