The Cold Mountain Oscar winner, sporting a gamine blonde crop, says her worst colouring nightmare occurred when she turned brunette for Miss Potter.

“What I didn’t know is the temporary stuff stains the inside of the shaft so you can’t get it out,” cringes the 38-year-old, pictured out in Manhattan with a mystery man bearing an uncanny resemblance to her ex, Jim Carrey.

“It mutated to Ronald McDonald red, then it faded to pumpkin. Then it was pink, then mango… Mango hair! Now that’s a look!”