It was really only a matter of time. After dying her hair cotton-candy pink, purple, blue and purple and blue, Katy Perry is even closer to a full rainbow after dying her hair green.

Slime green, that is.

The "Dark Horse" singer debuted her new 'do on Monday (April 7), just in time for spring. It's not completely green -- her roots and bangs are still her signature black -- but it's definitely a big change-up for the singer.

Perry has famously sported a bevy of bold hairdos, but what is it about these bright colors that Katy loves so much?

"Of course, being Katy, she is a lot more edgy and she's cooler and she likes to take a lot of risks. And I love that she's like, 'I'm feeling a little blue, let's go blue' -- not in her energy, just in her hair color," Perry's longtime hair colorist Rita Hazan told MTV News back in 2012, right after the singer debuted her bright-blue locks. "She's kind of this candy-coated sort of person. It's nice to see her experiment with different things."