Meghann Fahy is no longer a brunette. The actress underwent a dramatic 12-hour transformation — courtesy of celebrity colorist Matt Rez — to ditch her signature hue and become a blonde. To put that into perspective, 12 hours is about the length of a flight from New York City to Honolulu or even Dubai. In other words, it’s a very long time to sit in a salon chair. But judging by the results, it was more than worth it.

As you might expect, going from brunette to blonde in one day is not a simple process. In an Instagram video, Rez revealed all the details behind the all-day color overhaul. The transformation involved full color removal (which involves bleaching the hair to lift the dark pigment), followed by a combination of all-over colors, glosses, lowlights, and highlights. It’s a process that can seriously stress the hair if it’s not done correctly. To prevent any lasting damage, Rez relied on Epres Beauty’s Professional Bond Repair Treatment, writing in the caption that he couldn’t have completed the job without it. “It helped keep the integrity of her hair,” he also added about the product.

Fahy made the major change for an upcoming role. The Emmy-nominated actress is set to star in the film You Deserve Each Other, a romantic comedy based on a novel of the same name, alongside Penn Badgley.

After going blonde, Fahy was spotted on set with her new color styled in soft, loose waves. The shade definitely suits her — hopefully she keeps it long after the filming wraps.