The 29-year-old actress and her friend, makeup artist Rachel Goodwin, both got their hair permed, with Goodwin documenting the experience on her Instagram account on Wednesday.
In the slideshow, the Oscar winner and her pal are all smiles with orange and blue foam rollers in their hair and wearing black salon capes. There's also snaps of them sitting in the salon chairs and getting their hair treated.
"We have a permanent bond! Some friends get tattoos, well we get PERMS! We’re here to tell you that they are BACK and they are not your grandmas perm! Especially when you are in the amazing hands of @mararoszak and @bykileyfitz at @mare salon #curlyisthenewstraight #alltherage," Goodwin captioned the slideshow.
Stone is constantly switching up her hair color, transitioning back and forth from red to blonde. While she has been rocking red hair for the past couple of weeks, she was last spotted with lighter tresses in mid-December and at the 2017 Governors Awards in Los Angeles a month before that.
ET last caught up with Stone at the 2018 Golden Globe Awards, where she attended with iconic tennis player Billie Jean King. The duo spoke about the Time's Up initiative and how "we need massive systematic change."
Hear more of what they had to say in the video below.