Just 24 hours after showing off her newly-blonde locks, Jessica Alba has returned to being the brunette that made her famous.

E! News is reporting that the actress went blonde for her role of Victoria Knox in the upcoming film, "Barely Lethal." As most celebrities do these days, she showed off her newly dyed hair with a selfie on Instagram.

But a day later, according to The Daily Mail, she went "back to her roots," opting to return to the brunette locks that made her famous. In addition, when she initially went to blonde, she made sure that her locks weren't TOO light, so that she could go back to brunette pretty easily without damaging her lovely locks. When the paper caught her going into LAX on Monday morning, she was spotted wearing a hat over her head...leading to speculation that she cut her hair short because, despite her best efforts, it did indeed incur some damage.

Also according to the Mail, Barely Lethal revolves around a teenage assassin, played by Hailee Steinfeld, who fakes her death to get away from her employers and start a new life in the suburbs as a high school student.

So...do you prefer Jessica as a blonde or as a brunette? Leave your thoughts in the comments below!