The Palme d’Or is the highest prize awarded at the Cannes Film Festival each year, presented to the director of the best feature film. Past honorees have included such notable favorites as “Amour,” “Fahrenheit 9/11,” “The Pianist,” “Pulp Fiction,” and “Taxi Driver” — so it goes without saying that walking away with the Palme d’Or is no small feat. In fact, it pretty much guarantees an excellent and critically well-received film. But for once, you’ve probably never heard of this year’s winner, nor its stars (Léa Seydoux and Adèle Exarchopoulos), nor its director (Abdellatif Kechiche), nor the French graphic novel it’s based upon (“Blue Angel” by Julie Maroh). “Blue Is the Warmest Color” was much buzzed about during the festival, thanks in part to its reportedly “astonishing” 10-minute, likely unsimulated sex scene (helloooo, NC-17) between the two female lead characters. The film, which opens in American theaters on October 25, tells the rapturous story of Adèle, a 15-year-old aspiring teacher, who finds her world spun on its axis when she falls for Emma, an older, blue-haired art student. The trailer alone is absolutely stunning, set perfectly to a Beach House track. Prepare yourself for the chills.