Lily Allen Debuts Ultra-Long Fiery Red Hair — and Her Hairstylist Showed Off the Extension Process

Lily Allen is bringing the heat with her hair this winter!

The singer-songwriter, 38, debuted a show-stopping new hairstyle on Instagram on Monday, swapping her previously orange pixie cut for an ultra-long, firetruck-red ‘do.

Allen showcased her new look in a selfie, tucking her fiery red locks into a beanie as she posed by the subway tracks. She also complemented the new color with a practically identical shade on her lips.

The “Smile” singer let the pic — and hair — speak for itself, but did point out her new resemblance to Princess Ariel with a singular redheaded mermaid emoji in the caption.

Though Allen did not provide any hair details, Ester (@hairbyester), the hair extension specialist responsible for her new ‘do, dedicated a before-and-after post to the singer’s new look — and shared a behind-the-scenes look at the 11-hour extension process.

The N.Y.C.-based specialist shared a video on TikTok explaining that “when Lily Allen hits you in the DMs … you gotta answer,” adding that Allen’s old music videos “raised me.”

Ester went on to explain that Allen, who arrived with a short bob and faded orange hair originally only wanted extensions that fell at her shoulders, but changed her mind during the installation.

“When we met and I started doing the install and she started to see what the length was lengthin’ like … we kind of decided that we were just going to go all-in,” she said.

The thickness of Allen’s hair — combined with the fact that she is currently growing out a pixie cut — proved challenging, the hairstylist said. 

“I did what I could, but I don’t think either of us were really prepared for the intensity and the complexity of this install,” she said. “This was probably the most complex install that I’ve done to date, due to the really short hair and really dense, dense, thick hair that she had.”

After 11 hours, Allen’s extensions, which Ester said she custom-colored, were installed, and the specialist dubbed the look “wearable art.”

“Lily Allen, slay,” she finished the TikTok.

Never miss a story — sign up for PEOPLE's free daily newsletter to stay up-to-date on the best of what PEOPLE has to offer, from juicy celebrity news to compelling human interest stories.

Allen, who rose to fame while rocking dark brunette locks, bleached her chic black bob platinum in February and debuted the look on Instagram with a casual selfie and cheeky caption: “Can I speak to the manager ?”

Then, after several months of blonde, the “F--- You” singer switched things up again in September, arriving at Sofia Coppola's book launch with a new copper color.

At the event, a collaboration with Chanel, Allen fittingly paired her warm new ‘do with a black patent jacket and matching silk shorts from the designer. She attended with her husband of three years, David Harbour, who complemented her in a dark suit.