On June 2, 2021, an insider revealed that Lorde would be releasing the lead single from her long-awaited third studio album, "Solar Power, and a promotional single titled "Mood Ring". "Solar Power" was released on June 11, 2021, followed by "Stoned at the Nail Salon" on July 21. On August 16, Lorde updated her website announcing "Mood Ring" release for the next day.
In the pre-premiere live stream, she talked about the meaning of the song:
This is a song I am very excited about, it’s so much fun to me. Obviously when making this album I did a deep-dive into ’60s, Flower Child culture. I wanted to understand the commune life, dropping out from society and trying to start again. That really resonated to me when writing this album. One thing that occurred to me as a major parallel between that time and our time is our wellness culture and our culture of spirituality, pseudo-spirituality, wellness, pseudo-wellness. Things like eating a macro-biotic vegan diet or burning sage, keeping crystals, reading tarot cards or your horoscope. These were all things that they were dabbling in back then, and that me and my girlfriends are dabbling in today. I was like “I think there’s a pop song in here.” So this is kind of my extremely satirical look at all of those vibes.
In an email sent to fans for the release of "Mood Ring", Lorde revealed she wrote the song in late 2020.
I kept waking up in the night and writing lines of lyric into my phone, which is how I usually know something’s gonna become a song. It was really interesting distilling some thoughts on wellness culture and the search for spiritual meaning in our modern world into a 3-minute pop song.