The popstar unveiled her new darker locks over the weekend (8 February) as she promoted her new range of fragrances on Twitter.
In the photo, the 32-year-old is all smiles as she poses in a mirror while holding up one of her perfume bottles.
Showing that brunettes have just as much fun as blondes, Britney said: "Spice up Valentine's Day by getting 'Naughty & Nice' (pun intended) ;)."
Britney is currently in Las Vegas performing on her 'Piece of Me' show at the Planet Hollywood Resort and Casino. She kicked off her two-year Las Vegas residency on 27 December, where she will play more than 50 dates across a two-year period.
Last week, Lady Gaga flew over to Las Vegas to watch Britney perform, and the two singers posed for a photo seemingly showing off their signature blonde hair.
Now, however, we're wondering if Britney was actually covering up her newly-dyed brunette tresses with a wig?
This isn't the first time that the 'Toxic' hitmaker has switched up her hair colour, as last February, Britney unveiled darker locks at Elton John's Oscars party.
Britney also showed off dark chocolate locks in 2009 after getting together with her now ex-boyfriend Jason Trawick.
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Watch Britney's music video for 'Perfume' below: