The noise colours differ in exactly one measurable way: how the energy is distributed across frequency. White is flat, pink rolls off gently as pitch rises, brown rolls off steeply. Everything else — “brown noise is better for sleep”, “pink noise boosts deep sleep” — is interpretation layered on top of that one fact, and the layer is thinner than the internet suggests.
What the colours actually mean
Take any sound and ask how much energy sits in each octave: 100–200 Hz, 200–400 Hz, 400–800 Hz, and so on up. The answer is what the colour names describe.
| Colour | Energy across frequency | Sounds like |
|---|---|---|
| White | Equal per hertz — the high end carries the most energy per octave | A hiss, like untuned radio static |
| Pink | Falls about 3 dB per octave — equal energy per octave | Steady rainfall, a waterfall at a distance |
| Brown (red) | Falls about 6 dB per octave — strongly weighted to the bottom | A low roar: heavy surf, a distant motorway, a big fan |
One consequence explains most of the preference data you will see: human hearing is most sensitive in the range where speech lives, roughly 2–5 kHz. White noise puts plenty of energy there, which is why it can feel sharp or fatiguing — and also why it is the most effective of the three at covering conversation through a wall. Brown noise largely vacates that region, which is why people describe it as “warmer” and “less tiring”, and why it does comparatively little against a television next door.
Note also that brown noise is not named after a colour of light. It comes from Brownian motion, the random walk that produces the same spectral slope. Nothing about the name implies anything about sleep.
Does any colour actually improve sleep?
Here is the honest state of it. Pink noise has been studied more specifically than the others, usually in small lab experiments, some involving pulses of sound timed to slow brain waves during deep sleep. Those studies are interesting and genuinely produced measurable effects — but they are small, mostly short-term, and several used equipment and timing that a phone playing a loop does not replicate. Broader reviews of continuous noise for sleep have repeatedly landed on the same verdict: the evidence base is weak and inconsistent.
The trend towards brown noise, meanwhile, is essentially a preference story that spread through social media — people find the low rumble more comfortable, particularly people who find white noise abrasive. Preference is a perfectly good reason to choose a sound. It just is not a clinical finding, and phrasing it as one does nobody any favours.
So the practical hierarchy is: what you will tolerate for eight hours matters more than the colour; what you are masking matters second; the colour label itself matters least.
Choosing in five minutes
Pick by the problem you actually have.
| Your situation | Lean towards | Why |
|---|---|---|
| Voices, a TV, a shared wall | White, or rain | Speech-range energy is what covers speech |
| Traffic, a bass line, footsteps above | Brown-leaning: fan, waves, low rumble | Matches the frequency range of the intruding noise |
| White noise gives you a headache | Pink-leaning: steady rain | Same broadband coverage, less high-frequency bite |
| Nothing specific — the room is just too still | Any, quietly | You want a floor, not a mask; volume matters more than colour |
Getting each character out of Pease
Pease ships one literal noise generator — White Noise — and no tracks labelled “pink” or “brown”. That is deliberate: natural recordings are pleasanter to sleep beside than synthesised noise, and several of them sit naturally in the pink and brown parts of the spectrum. Rather than pretend otherwise, here is how to get each character from what is there:
- White-ish: White Noise at 35. The flattest, most broadly masking option in the library, and the harshest — keep it lower than feels natural.
- Pink-ish: Rain 45 with White Noise 15. Steady rain is close to a pink slope already; a whisper of white fills the gaps between droplet textures.
- Brown-ish: Fan 45, Ocean Waves 30, Wind 15. Low-weighted and rumbling, with the high end left mostly empty.
These are approximations by ear, not measured spectra — the point is the character, not a claim that Rain equals a pink-noise generator.
How to test properly
Colour comparisons fall apart when the volumes are not matched. Brown noise at the same slider position as white sounds quieter, because most of its energy sits where your ear is less sensitive — so people conclude it is “gentler” when they have simply turned it down. Level the playing field:
- Play one option at the quietest level that still covers the noise you care about.
- Switch to the next and adjust it to the same subjective loudness before judging the character.
- Give each one three nights. The first night with any new sound is about novelty, not sleep.
- Change nothing else in that window — same bedtime, same timer, same room.
Whatever you land on, keep it quiet: the volume rule outranks the colour choice by a wide margin. And if what you are really fighting is one specific noise rather than a general restlessness, start instead with masking versus blocking.