We don't know about you, but these stars were feeling a bold new hue.

Emily Ratajkowski and Florence Pugh decided to heat things up this summer when they stepped out with fiery hair colors, both opting for brighter tints: The model revealed she had "gone red" in a July 18 Instagram post, while Pugh dyed her buzzcut a seasonally appropriate shade of tangerine. And they weren't the only stars to switch up their looks this week: Zoe Saldana said "oui oui!" to a French-inspired bob that is making us want a croissant real bad. 

Meanwhile, Cillian Murphy opened up about the drastic changes he made to his diet in order to shed weight to portray real-life "father of the atomic bomb" J. Robert Oppenheimer in the summer blockbuster Oppenheimer. Finally, two HGTV stars unveiled the final results of their lifestyle renovations, including Flipping 101 host Tarek El Moussa, who shocked fans with his fitness transformation.

Check out the most surprising celeb transformations of the week: 

The rest of the summer is going to be red hot for this model.

Ratajkowski said goodbye to her signature brown tresses for a fiery red hue, debuting her new hair color in a July 18 Instagram post. 

In the snapshots, the My Body author is posing on a couch as she shows off her freshly dyed locks, captioning the images, "gone red."

Saldana's new look is très chic.

The actress debuted a French-inspired bob at the London premiere of her new series Special Ops: Lioness July 11.

"Someone got a MAJOR summertime Frenchie Bob chop," Saldana's hairstylist Mara Roszak wrote on Instagram.

Orange you loving this look?

Pugh ditched her pink locks for a fiery hue at the Oppenheimer premiere July 13. The Little Women star's vibrant buzzcut matched her tangerine Valentino gown. Pugh's go-to hairstylist Peter Lux showed off the actress' new look on Instagram, writing, "Golden hair for @oppenheimermovie premiere," adding several flame emojis.

Her makeup artist Alex Babsky's work complemented the bold hair change, the pro captioning an Instagram post, "Flame-haired Florence."

Now that is commitment.

For his turn as J. Robert Oppenheimer in Christopher Nolan's Oppenheimer, Murphy underwent a dramatic transformation.

"Oppenheimer had a very distinct physicality and silhouette, which I wanted to get right," the 47-year-old  explained to the New York Times of the famous scientist, who died from cancer in 1967. "I had to lose quite a bit of weight, and we worked with the costume and tailoring; he was very slim, almost emaciated, existed on martinis and cigarettes."

The Irish actor's costar Emily Blunt, who plays Oppenheimer's wife Kitty, detailed the jarring diet Murphy subscribed to in order to portray the father of the atomic bomb.

"He had such a monumental undertaking," she told Extra. "And he could only eat, like, an almond every day."

Fans are flipping out over the HGVT star's fitness transformatin after El Moussa posted before and after photos in a July 21 Instagram post.

Reflecting on his wellness in the throwback photo from two years ago, El Moussa wrote "sometimes you think you're doing the right thing but what you actually need is redirection in order to see growth. In that photo I was doing some hot yoga, wasn't really on any kind of schedule, wasn't tracking my protein intake, and didn't really have any guidance."

But after changing his approach to fitness, El Moussa saw results.

"I'm up early every AM to workout, I have a solid routine, I'm taking the right supplements," the Flipping 101 host noted. "I'm eating the right food & Hot yoga 1-2 times a week which is so good for my mental & physical state."

Now this is quite the renovation. 

The Home Town star showed off the results of the health journey he embarked on earlier this year in an July 17 Instagram video posted by his wife and costar, Erin Napier.

"@scotsman.co got hardcore about his health and fitness last winter ahead of his big shoulder surgery that was in march so he could sleep better on his back and lower his BP," Erin wrote in the caption. "mission accomplished." 

Ben commented on the post, "What ya think, @people? Can I make the top 50 again?" referring to his placement in People's Sexiest Man Alive issue in 2021. "That's my real motivation."