Ashley Tisdale says going blonde was the key to her success

High School Musical star Ashley Tisdale has revealed the secret of her success - going blonde.

The 22-year-old actress - known for her role as 'Sharpay' in the hit Disney show - was originally a brunette - but only got her big break after changing her hair color.

She said: "It suits my personality. I guess I was a brunette with a blonde personality.

"I have been blonde for a while now.

"At first it was really shocking and I didn't know what to think, it felt like another person in the mirror. But now I am comfortable with it.

"But blondes aren't dumb. I am smart and I don't think all of us are ditzy."

Changing hair color has clearly worked wonders for Ashley; in just under three years, High School Musical - which is set for the big screen later this year - has turned the young singer/actress from a virtual unknown into a global superstar and her debut pop album 'Headstrong' has sold more than a million copies.

But despite her success, Tisdale insists that she is nothing like spoiled, selfish brat Sharpay - and is determined to avoid the traps that have snared teen idols such as Britney Spears and Lindsay Lohan whose soaring success has led to wild behaviour and stints in rehab.

She said: "I don't drink, I don't smoke and I don't go clubbing so a lot of those problems go away.

"The difference is I play young but I am 22 and have been in this business since I was three years old.

"It just depends how you were raised but success does come early for some people.

"Lindsay and Britney had success really early and that is a lot a pressure.

"For me, I am glad that it came at this time and I got to finish high school.

"I know who I am and what I want from life and I am mature about life. I am able to go out there and get what I want."