The "Dark Horse" singer posted an Instagram pic on Monday showing off her new hair, which was dyed a vibrant shade of green, save for her bangs and roots which were kept a dark shade of black.
"SLIME GREEN FOR SPRING by my bb's @neeenaboo & @brantmayfield at the @mcmillansalon," Katy captioned the photo.
Green has been on Katy's radar for a while- John Mayer's ex told E! Online in March that she had been thinking about changing her colour for a while.
"I've wanted to go slime green for a long time," she said. "It's spring time and I think it's time to freshen up my look."
Here's what we want to know: does the hue go well with all her kooky outfits?
Katy's hair was really different back in the day: