Chris Appleton is a celebrity hair artist and Global Artistic Director for Glam Seemless (often colorful hair extensions). His work (often temporary) can be seen on the Jenner/Kardashian women, Jennifer Lopez, Ariana Grande, Katy Perry and more.
In September 2018, he turned Kylie Jenner's hair this wonderful Barbie pink, using semi-permanent frosting color that's 100% Vegan & Cruelty-Free. According to Chris's Instagram post, "To get the look I was super gentle on the hair and used Lime Crime Makeup Unicorn Hair Tint in Kawaii and Bunny and used Lime Crime’s Dilute Hair Mixer to make a super soft frosted pink."
See more pink hair bef-afters (including one for Kylie's sister Kim also done by Chris Appleton) via links 1 and 2 below. And see Chris's Instagram post about this treatement he did for Kylie via link 3. Finally check out Lime Crimes hair tint color options via link 4.