The lesbian love story Blue is the Warmest Colour: The Life of Adele won the Palme d'Or Sunday at the 66th annual Cannes Film Festival in France.

The film, based on the French graphic novel Le Bleu est un Couleur Chaude (Blue is a Warm Colour) by Julie Maroh, was directed by Abdellatif Kechiche and stars Adele Exarchopoulos and Lea Seydoux.

Exarchopoulos stars in the French film as a 15-year-old girl who is certain girls must date boys. Her life is transformed when she meets and falls in love with an older woman, played by Seydoux.

The jury awarded the prize not just to the film's director but also to its two stars. Steven Spielberg, the head of the jury, announced the unusual move from the stage.

“The film had a beautiful French youth that I discovered during the long time filming the movie,” the Tunisian-born director said on Sunday. “It taught me a lot about the spirit of freedom.”

“The film is a great love story that made all of us feel privileged to be a fly on the wall, to see this story of deep love and deep heartbreak evolve from the beginning,” said Spielberg. “The director didn't put any constraints in the narrative, on the storytelling. He let the scenes play as long as scenes play in real life.”

The film had previously received wide attention due to its graphic sex scenes.