Michelle Williams let Busy Philipps dye her hair pink.
The 37-year-old actress made the brave decision to let her 38-year-old pal loose on her blonde pixie bob, even though the 'White Chicks' star had been drinking alcohol, and Busy documented the makeover on social media.
Speaking in a string of videos on her Instagram Story, Busy said: "We're going to dye her hair pink. What do you think? Is this a good idea? Alright guys, here we are. I am going to dye Michelle Williams' hair. Are you ready?"
Although the hair colour was meant to stay on Michelle's locks for "20 minutes", Busy decided to cut down the time to one quarter of the time advised.
She explained: "You have to put it in for 20 minutes. I have it in my hand. It's like pink slime. We will do it for like five minutes."
However, the 'Manchester By The Sea' star - who has 11-year-old daughter Matilda with her late husband Heath Ledger - wanted to slash the time the dye was meant to stay on her hair even more.
Michelle replied: "Three minutes, two minutes, honestly like after one minute we should stop."
Busy compromised with Michelle and after massaging the product into "the little pixie's hair", they planned to wash out the substance in "two minutes".
As Busy slurped on a glass of wine, she said: "Guys, I am putting the pink in. I am massaging the pink into the little pixie's hair. Michelle's hair is going to be perfectly millennial pink. She is going to wash it out in two minutes and it is going to be amazing."
Busy and Michelle continued to show their fans the outcome of the beauty session, and Busy hailed her friend as "a little nymph" with "slightly pink" tresses.
Busy concluded her post by saying: "Guys my best friend now has ... I mean, she is kind of naked, and she has slightly pink hair and it is f**king beautiful. Michelle's hair is slightly pink and so cute. And look, she is like a little nymph asleep next to me. "