New hair. Who is this?

It's Millie Bobby Brown with a brand new Barbie-like blonde look.

The "Stranger Things" star stunned fans when she posted a photo of herself with way brighter strands. She posed alongside her boyfriend, Jake Bongiovi, who also appeared to go lighter with his hair.

Brown simply captioned the image "hey ken!" with a birthday cake emoji -- coinciding with her 18th birthday this weekend. Bongiovi posted the same photo, and said, "Happy birthday barbie ily."

Since posting, Brown's post has received more than five million likes with many people wishing her a happy birthday and saying how great she looks.

Some fans also commented how she wasn't as recognizable with her new blonde look. On Twitter, @keeryluv called for a petition for the actress to dye her natural hair blonde as her new color does appear to be a wig.

"Blonde is her color!!!" the tweeter wrote.

The mane man behind Brown's new head-turning look is celebrity hairstylist Pete Burkhill.

"Thanks for trusting us to have so much fun with your lewks," he wrote in a post next to a photo of the couple.

While lots of people were surprised by Brown's new look, it isn't the first time she's gone blonde.

In 2019, the then 15-year-old actress showcased a caramelized blonde look while promoting her beauty brands florence by mills.

Brown has also worn a variety of different cuts, with styles throughout the years including everything from beach waves to stick straight pulled back updo looks.