Move over white noise—pink noise is the latest trend gaining popularity among people seeking better sleep and deeper relaxation. This softer, more soothing sound is fast becoming a go-to tool, alongside brown and green noise, in what some call a 'rainbow of relaxation.' Each of these coloured sounds is believed to influence sleep, focus, and overall calm—but is there any science to support the claims?What Is Pink Noise?Though the research is still in its early stages, that hasn’t stopped people from spending hours listening to these sounds on YouTube or through meditation apps that now offer curated colour-noise playlists under paid subscriptions.To understand pink noise, it's helpful to first look at white noise — the most well-known of the group. White noise resembles the static heard on a television or radio and is defined by sound engineers as containing equal volume across all frequencies detectable by the human ear. It gets its name from white light, which contains all visible colour wavelengths.However, white noise’s high frequencies can be harsh. That’s where pink noise comes in — it reduces the intensity of higher frequencies, producing a softer, lower-pitched sound similar to rain or ocean waves. Brown noise goes even deeper, offering a richer rumble that many find soothing.While pink, white, and brown noise have clear definitions in audio engineering, other colour noises—like green or blue—are newer and more loosely defined.What Does Research Say?Though still limited, there’s some emerging science behind colour noises. A recent review of small studies found that both white and pink noise may offer minor benefits to people with attention-deficit/hyperactivity disorder (ADHD). According to Joel Nigg, an ADHD researcher at Oregon Health & Science University, these noises may stimulate the brain without offering actual information—which helps prevent distraction.White noise has also been used in tinnitus treatment—helping mask the ringing or buzzing in the ears. Meanwhile, scientists at Northwestern University are exploring how short bursts of pink noise might boost slow-wave brain activity during deep sleep. Preliminary studies suggest that these pink noise pulses could enhance memory and promote relaxation.Dr. Roneil Malkani, a neurology professor at Northwestern University Feinberg School of Medicine, explains that pink noise closely mirrors the natural frequency distribution of brain waves seen during slow-wave sleep. This similarity could help explain its calming effect. If the research holds up, it may lead to devices that use personalised pink noise to improve memory or sleep quality. However, Dr. Malkani cautions that “there’s still a lot of work we have to do.”Is It Safe to Try?If colour noises feel relaxing or help block distractions, they can be a helpful tool. Just be mindful of volume. “Keep it quiet to avoid hearing damage and give your ears regular breaks,” Nigg advises. As the trend grows, pink noise may prove to be more than just a fad, offering a gentle, non-invasive way to improve rest and well-being.ALSO READ: What Is Moon Breathing? How Does It Promote Sleep?