The 28-year-old ditched her usually polished style for a more grungy look, complete with biker boots and a black leather jacket.
It was soon revealed that Amber's dramatic new hairstyle was actually a wig, which she was wearing during filming for her latest film When I Live My Life Over Again, in which she stars opposite Christopher Walken.
Click on the image below to see which other celebrities have sported hair bright coloured hair.
Amber celebrated her birthday on Tuesday with Johnny Depp with a dinner at II Buco Italian restaurant in Manhattan, wearing a stunning red velvet coat over a red lace dress. The couple confirmed their relationship in June 2012, and got engaged on Christmas Eve.
"She's a wonderful girl," said Johnny in a recent interview. "She is sharp as a tack. A southern belle and sweet as can be, and very good for me."