The pop songstress was spotted out and about in Los Angeles with her boyfriend David Lucado and her eldest son Jayden James on Saturday (1 March) and was almost unrecognisable in her low-key gear.
Opting for comfort over style, Britney covered up in a stripy long-sleeved top, leggings and some sunglasses.
She also sported a pair of wedge trainers and some colourful socks, while showing off her new brunette locks.
Last month, 32-year-old Britney unveiled her latest brown hair 'do as she promoted her new range of fragrances on Twitter, ditching her trademark blonde tresses.
And she appears to be liking her brand new look, since she's been embracing the darker shade on stage in Las Vegas and even encouraging boyfriend David to try the brunette hairstyle out too!
After her laid-back Saturday, Britney then got glammed up in a sheer, figure flattering gown for Elton John's 22nd Annual AIDS Foundation Academy Awards Viewing Party in Hollywood, which took place on Sunday night (2 March).
Ditching her comfy loungewear, the mum-of-two was completely transformed at the start-studded bash and confidently posed for the cameras in her cleavage-flashing dress.
She completed her red-carpet-ready look with an eye-catching choker necklace and styled her long brown hair into large curls.
The chart-topper was joined on the evening by her beau David, who smartened up in a dapper black suit and bow-tie.
Before heading out, Britney tweeted a photo of the couple together and wrote: "Getting ready to go to Elton and David's party! Love this amazing event that's for a great cause :)"
Also at Elton's charity viewing event was Kelly Osbourne, who used the opportunity to settle her feud with Lady Gaga, and Kim, Khloe and Kourtney Kardashian.
What do you think of Britney's figure flashing dress? Let us know, as the best comment from across the website each week wins £50!
Check out other Oscars outfits from Sunday night in our gallery.
Copyright: Rex Features Startraks Photo
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