The former Strictly star posted this selfie up of her Native American make-up for her birthday night out [Pixie Lott/Instagram]
Addressing the backlash for the first time, the 24-year-old beauty told OK! online: "I did see it all, and I am honestly so sorry if I offended anyone, it was never intended to happen.
"I apologise but I honestly meant it as an innocent thing," she said.
The Cry Me Out hitmaker was bombarded with Twitter trolls after she had posted up birthday photos wearing the costume.
Last night on the NTAs red carpet, Pixie also said: "Life has been amazing after Strictly, I loved the experience and I loved dancing every week, it was so fun.
"Now it's probably time to get back into my music. I'm in the studio all the time writing for my next album, which I'm very excited about," she added.
Last night, the singer put on a show-stopping performance at the National Television Awards, when she sang a rendition of The Proclaimers' I Would Walk 500 Miles to introduce David Tennant's Special Recognition Award.
A loved-up Pixie has been dating British model Oliver Cheshire for four years, but she claims the couple aren't quite ready to walk down the aisle just yet.
"We never plan anything, we just go with the flow and we're really happy with everything as it is and there's loads that we both want to do this year, so we'll just see where the wind takes us!" the singer coyly added.
Oliver Cheshire has recently opened up about his plans to marry and start a family with Pixie Lott [Wenn]