The actress shared a selfie of her new hairdo on Instagram for her role in the upcoming movie Love Hypothesis.&nbsp;

<a href="https://www.lofficielusa.com/pop-culture/lili-reinhart-announces-bisexual" target="_blank" rel="noopener">Lili Reinhart </a>made her name playing the famously blonde Betty in <a href="https://www.lofficielusa.com/fashion/exclusive-madelaine-petsch-riverdale-interview-riverdale-sustainability-video-series" target="_blank" rel="noopener">Riverdale</a>. Now she's left the hair color behind, showing off a brunette bun in her newest Instagram post. The actress is gearing up for her role in the screen adaptation of Love Hypothesis&nbsp;by Ali Hazelwood, where she is slotted to play the lead character, Olive. Reinhart snapped a picture holding up the&nbsp;Love Hypothesis&nbsp;book, wearing a dark, messy bun and white jacket similar to Olive's look on the cover. She captioned the post "👀🧬❤️&nbsp;<a class="x1i10hfl xjbqb8w x1ejq31n x18oe1m7 x1sy0etr xstzfhl x972fbf x10w94by x1qhh985 x14e42zd x9f619 x1ypdohk xt0psk2 xe8uvvx xdj266r x14z9mp xat24cr x1lziwak xexx8yu xyri2b x18d9i69 x1c1uobl x16tdsg8 x1hl2dhg xggy1nq x1a2a7pz _aa9_ _a6hd" href="https://www.instagram.com/explore/tags/thelovehypothesis/" role="link" tabindex="0">#thelovehypothesis</a>," letting her followers in on her exciting casting.&nbsp;

Reinhart is starring in the film alongside Tom Bateman, who's playing her love interest, Adam. For those who aren't fans of Hazelwood's hit romance novel, the story follows Olive, a Ph.D. student who fakes a relationship with her professor, Adam, to convince her best friend that she has moved on from her ex. But it only takes a glance to know that Olive and Adam's relationship grows into something deeper than what was intended.&nbsp;
The actress has had a busy year as she has already starred in The American Sweatshop, where she played the main character, Daisy Moriarty. Though in that film, Lili Reinhart remained blonde. Her co-star Tom Bateman, the British actor in&nbsp;Behind Her Eyes&nbsp;and&nbsp;Murder on the Orient Express, is also getting fans talking, as he may be more personally involved in the plot than one might expect. The actor is married to Daisy Ridley, a fan favorite for her roles in&nbsp;the&nbsp;Star Wars franchise, who also happened to be Hazelwood's inspiration for this very fanfic, meaning this casting can't be a coincidence.&nbsp;
Whether it's Reinhart's new locks or Bateman's connection to the story, this movie is already shaping up to be as entertaining off-screen as it will be once released. The Love Hypothesis&nbsp;is currently in production, and there is no official release date, but in the meantime, we can only hope for more behind-the-scenes photos from the newly brunette actress.

Getty Images.

Lili Reinhart Debuts Her Brunette Locks Ahead of New Role

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L'OFFICIEL USA December/January 2026  - Kelly Rowland Cover

Lili Reinhart Debuts Her Brunette Locks Ahead of New Role

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