In the beginning, Clémentine meets a boy, Thomas, who is a student in Terminale (final year of lycée, the French equivalent of senior high school or sixth-form college); they like each other, but soon afterward, Clémentine becomes intrigued by a chance meeting with a blue-haired young woman on the arm of another woman, Sabine Decocq.

Unable to forget this encounter, she starts to have doubts about her sexuality, but decides to date Thomas because she wants to feel normal.

Clémentine then has to face the gossip and homophobic taunts from some of her schoolmates when they hear that she and Emma were at a gay bar together.

Emma starts to become politically involved and takes part in LGBT activism, while Clémentine prefers to keep her sexuality private.

Still in love with each other, they reconcile, but Clémentine is undone by her addiction, which results in a seizure that puts her in the hospital, where Emma discovers that she is not allowed access to her at first.

Clémentine's parents and Emma eventually learn that it is too late to save her; the damage from the drugs is too great.

[5] A film adaptation was made by Abdelatif Kechiche, with Léa Seydoux and Adèle Exarchopoulos in the main roles, released in 2013[9] under the title Blue Is the Warmest Colour.

Like the book, it received great critical acclaim, winning several awards, including the Palme d'Or at the 2013 Cannes Film Festival.

Sepideh Jodeyri, an Iranian poet in the Czech Republic, made a Persian translation, as Abi Garmtarin Rang Ast.