Following a run a festival appearances, Cannes Film Festival Palme D’Or winner “Blue is the Warmest Color” is opening in North American theaters.

The French drama’s lengthy lesbian sex scenes and the post-Cannes public squabbles between the film’s director and its female leads have stirred controversy of the kind that can’t be bad for a 3-hour-long French-language film. Most French films, with their typically long scenes of dialogue and conversation, don’t even dent the U.S. box office.

Controversy aside, “Blue is the Warmest Color,” directed by French-Tunisian filmmaker Abdellatif Kechiche, has some exceptional things going for it. Most of all there’s Adèle Exarchopoulos, the 19-year-old actress who plays the story’s leading character, also named Adèle.

Kechiche keeps his camera on Exarchopoulos’ face an extraordinary amount of the time. In close-up as Adèle, the actress projects a heady array of thoughts and emotions. Adèle, a high school student in the northern French town of Lille, is on a life-altering journey. Exarchopoulos makes the journey breathtaking. Of course, there are tears.

“Blue is the Warmest Color,” from start to finish, is Adèle’s story. By contrast, Léa Seydoux’s Emma, Adèle’s lesbian lover, is a sketch, a storytelling device that facilities Adèle’s evolution.

Adèle, on her way to a date with Thomas, a boy at school who’s taken an interest in her, catches a quick glimpse of blue-haired Emma on the street. Emma is with another young woman, the two of them in a fearlessly public embrace.

Thomas seems like a nice boy, but he and Adèle have nothing in common. He doesn’t like to read. They don’t like the same music. None of this discourages Thomas. Adèle is a beautiful girl.

Adèle gives her brief relationship with Thomas everything she can give. She’s left unfulfilled. The bewildered girl confides in her openly gay friend at school. She later goes to a gay club with him. And then she not so accidentally leaves and makes her way to a lesbian club. Emma wasn’t difficult to find.

“Why are you here all alone?” Emma asks Adèle. In the bar, the worldly Emma, a college senior studying art, turns protective of newcomer Adèle.

Emma and Adèle meet again in a park. The film’s storytelling turns almost perfunctory when Emma and Adèle, unlike Thomas and Adèle, find they have so much in common. But sex is the prime motivator. Adèle turns especially lustful, which leads to the film’s visceral, much-written about lesbian love scenes.

In a less flashy way, the film is a double account of discovery. Adèle, a girl from a working-class upbringing that includes dull family meals in front a TV, is ready for a life less average. The higher-class Emma introduces her to fine art and cuisine. There’s resonance, beauty and joy in these scenes.

In the end, it all comes back to Exarchopoulos as Adèle. Working in France since she was 9, Exarchopoulos is a great actress. She, more than anyone, makes “Blue is the Warmest Color” glow.