The singer revealed her new look in a video posted to her Instagram on Thursday 20 January, where she showed off long, lilac waves.
Posing in a bathroom mirror wearing a black mini dress and red calf-length boots, Spears showcased how new hairdo both loose and tied up in a ponytail.
“Here’s me with purple hair,” the 40-year-old wrote in the caption. “I’m bored, ok??? Very bored so my nail girl said do it!”
She added: “Girl…I did it but not sure I like it but hey…Here’s me in a 100-dollar mini dress with my boots.”
The video has already been liked more than 300,000 times, with followers praising the singer’s new hair colour in the comments.
“Queen of purple,” one person commented. Another wrote: “So pretty. Bring back the mermaid hair.”
The change comes amidst an ongoing dispute between the Baby One More Time singer and her sister, Jamie Lynn.
During an interview with ABC’s Good Morning America ahead of the release of her memoir, Things I Should Have Said, on 18 January, Jamie Lynn claimed that Britney had once locked the pair in a room together with a knife because she “didn’t feel safe”.
Shortly after the memoir’s publication, Britney’s lawyers sent her younger sister a cease-and-desist letter, writing that the book is “ill-timed” and contains “misleading or outrageous claims” about the singer.
The letter accused Jamie Lynn of exploiting Britney for monetary gain.
“Although Britney has not read and does not intend to read your book, she and millions of her fans were shocked to see how you have exploited her for monetary gain. She will not tolerate it, nor should she,” it said.
It added: “Publicly airing false or fantastical grievances is wrong, especially when designed to sell books. It is also potentially unlawful and defamatory.”