“Bye bye brown hair.” That’s what Jessica Alba Tweeted on Thursday afternoon before lightening her dark mane and going blonde, marking the first time the actress has changed her hair color since 2009. (In Hollywood years, that’s an eternity to stick with one shade.)

Three days later, Alba took to Twitter again and followed up with another set of photos, showing off her new, ombré locks in this picture (left).

Alba is known for constantly switching up her style and taking risks with new trends, but is typically not as experimental with her hair. So this change feels especially drastic (though not quite as drastic as that other star who also recently debuted a new hairstyle).

But Alba didn’t go lighter just for the fun of it; she’s reprising her role as blonde stripper Nancy Callahan in a sequel to 2005′s Sin City. (You also may recall a blonde Alba in the 2005 and 2007 Fantastic Four films, too.)

Directors Frank Miller and Robert Rodriquez are teaming up again for the sexy, graphic-novel-inspired Sin City: A Dame to Kill, which has a release date set for Oct. 4, 2013.

沪江娱乐快讯：好莱坞辣妈杰西卡·阿尔芭向来是潮流先锋，不过她对于自己的棕发造型似乎格外专一。这在当今热衷变换发色发型的好莱坞女星中实属罕见。如今，为了再度演绎电影《罪恶之城2》中的脱衣舞女郎Nancy，她毅然告别保留了三年的棕发，华丽变身金发女郎。杰西卡第一时间在个人推特上与影迷们分享了自己的新造型。

相关链接：《罪恶之城2》确定上映日期 辣妈杰西卡•阿尔芭回归