Avril Lavigne's new hair is complicated.

The 27-year-old engaged singer-designer debuted her fresh bold 'do Monday night at her Abbey Dawn show during Mercedes-Benz Fashion Week. The left side of her head was partially shaved, and she dyed her remaining long locks hot pink and neon green.

"Tonight I got a little wild with my hair dye in my hotel room," she told Us Weekly. "I've always dyed my hair and had fun with pinks and greens, but this evening I was celebrating Fashion Week, here in New York, and the fact that I'm having a runway show, which is a major deal for me and means a lot."