Katherine Heigl is refusing to dye her hair again.

The actress coloured her locks from blonde to brunette for upcoming movie 'One for the Money' but needed to go back to her roots to promote her other film 'Killers'.

However, instead of going through the hassle of hair colouring again, Katherine has now discovered she can achieve the blonde look by wearing a wig.

She said: "I did it about a month ago... I'm supposed to have dark hair for 'One for the Money' and recently discovered the beauty and the wonder of a really well-done wig.

"I did have to go back to blonde for poster shoots for a film I have coming out this summer, 'Killers', and the wigs are so fantastic I thought from now on I should just wear wigs. It takes half the time."

Katherine recently revealed she was "shocked" when she dyed her hair dark.

The mother-of-one - who is married to musician Josh Kelley - said: "I was pretty shocked at first... I was like, 'wow, it's dark, that's not just brown, that's black.' It took me a good day and a half to totally embrace it.

"Josh just freaked out immediately. That's good at least that the boys like it. I love it. It's fun. I feel a bit different even though I don't act any different. I say all the same stupid things - I just look different."