Ashley Tisdale knows it sounds silly, but her new album has a lot to do with the color of her hair.

"For the last few years everyone has thought of me as Sharpay," the 23-year-old singer/actor says, referring to her blonde-and-bubbly character in Disney's smash "High School Musical" films.

"So after I'd finished all the promotion for 'High School Musical 3' I dyed my hair back to its original color. I'd been a blonde for five years; Disney wanted us to be those characters. But the new songs I was working on felt edgier, sort of back to how I was before 'High School Musical.' I wanted to show people a side of me they haven't seen before."

Tisdale accomplishes that -- well, sort of -- on "Guilty Pleasure," due July 28 from Warner Bros. Like her 2007 debut, "Headstrong" (which, according to Nielsen SoundScan, has sold 471,000 copies in the United States), the new 14-track set offers plenty of catchy choruses and lyrics about boys.

But with songwriting and production credits from "American Idol" judge Kara DioGuardi, among others, "Guilty Pleasure" is a more mature, guitar-driven outing than the dance-pop "Headstrong." In the opener, "Acting Out," she promises to "break these chains" over driving bubble-punk drums, while the lead single, "It's Alright, It's OK," could be the younger sister of Pink's "So What."

"A lot of the songs on the album are about survival and staying strong," says Tisdale, who co-wrote four cuts. "I really wanted it to be a statement and a reflection of what I've been through over the past year and how I've grown up."