It was written by Dijon McFarlane, Nicholas Audino, Te Whiti Warbrick, Lewis Hughes, Jon Asher, and Melanie Fontana.

Later, Sony Music issued the song to radio airplay in Italy as the third single from Glory on July 10, 2020, almost four years after the album's release.

"Mood Ring" was written in February 2015 by American songwriters Jon Asher and Melanie Fontana, two self-proclaimed fans of Spears.

[5] Following the rework of the song by DJ Mustard, Asher and Fontana were informed in early April 2015 that Spears "has put [their] demo on a hold" with Omar Grant and the Roc Nation team.

During the writing process, the duo had "full-on Britney brain" and imagined the singer performing the song on stage and in a music video.

Its lyrics focuses on Spears "deciding between two versions of herself" to present to a possible suitor, demonstrating through the first lines "Look in the mirror, who do I see?/Who do I wanna be today?"

[11] Following the #JusticeForGlory campaign that was launched by Spears' fans on social media during the COVID-19 pandemic, the singer unveiled a new cover art for Glory on May 8, 2020, nearly four years after its release.

[12] Three weeks later, Spears announced that "Mood Ring" would be released worldwide on all streaming and download platforms the next day, subtitled "By Demand" to credit her fans for their support of the album.

Lewis Corner from Digital Spy welcomed it as "a very nice addition indeed", calling it "a sultry slow jam that hears Britney at her most seductive.

"[9] Writing for Soundazed, Matt Torres called it a "bop" noting "the hypnotic melody and trap-inspired electropop create a lush soundscape for Spears as she sings about her chameleonic love.