The Valentine's Day actress proved herself to be quite the colour chameleon by going from brunette to blonde, then back to brunette in the space of just a few days. Impressive!
Back in September Jess was rocking a super-long caramel mane before chopping it into a sexy tousled bob, complete with a fierce dip-dye.
But never one to stick to just one hairdo, then starlet showcased newly-dyed beach blonde locks in an Instagram snap on Sunday (24 November).
She took the doe-eyed selfie while relaxing in between takes of her new flick Barely Lethal, adding the caption: "#victoriaknox #selfie @barelylethalmovie taking a break btwn takes - hiding out in a rm - all this #action and #stunts r exhausting."
Another picture shows the mother-of-two with her lighter locks styled in loose curls while posing alongside the film's director Kyle Newman and master stunt coordinator Andy Cheng.
But just as we thought she might officially be back to her blonde Sin City ways, the actress posted yet another selfie yesterday (26 November), this time rocking brunette tresses.
She was snapped the same day giving her new bonce its first outing while heading to The Honest Company offices in Los Angeles.
Looking cool, casual and oh-so-chic, Jessica wore a pair of printed trousers paired with a leather jacket and a pillar-box red handbag.
As for her hair? A side parting plus a quick brush and she was looking picture-perfect in no time. Jealous!
Got an iPad or iPhone? Reveal Mag has been especially designed to fit!
Do you think Jessica suits blonde or brunette hair better? Let us know by commenting below as the best comment across the site each week wins £50!