The colors of noise
White, pink, brown, green — and the exotic ones nobody plays. One honest chart, four playable colors, zero mysticism.
| Color | Spectrum | Sounds like | Used for | Listen |
|---|---|---|---|---|
| White | Equal energy at every frequency | Static, hard rain | Masking sharp sounds; the classic | |
| Pink | −3 dB per octave (softer highs) | Steady rainfall | Balanced sleep sound; studied for deeper sleep | |
| Brown / Red | −6 dB per octave (low-heavy) | Waterfall, plane cabin | Deep sleep feel, ADHD-community favorite | |
| Green | Mid-band (~200-900 Hz) | Wind through trees | The "natural" middle ground, rising fast | |
| Blue | +3 dB per octave (bright) | Sharp hiss | Audio dithering; rarely for sleep | — |
| Violet | +6 dB per octave (very bright) | Piercing hiss | Signal processing; sometimes tinnitus tests | — |
| Grey | Loudness-corrected white | Tilted static | Psychoacoustics experiments | — |
| Black | Near-silence | (nothing) | A poetic name for quiet | — |
The four playable colors come in three depths each — switch in the bar below. Deep-dives: brown · green · the full comparison.
Why "colors", anyway?
It's an analogy to light. White light contains every wavelength equally — white noise contains every audible frequency equally. Tilt the energy toward the low end and, as with light shifting toward long wavelengths, you get "red" (brown) noise; tilt it toward the highs and you get blue and violet. Pink sits between white and red, exactly as in the light spectrum. Green is the loose one — named for sounding like nature rather than for a strict spectral formula. The analogy breaks down at grey and black, which are really psychoacoustics terms — but by then the naming convention had taken on a life of its own.
What matters practically: the tilt decides the texture. More energy in the highs = hissier; more in the lows = rumblier; concentrated in the mids = more "natural". Every claim beyond that — this color heals, that frequency detoxes — is marketing. Masking and comfort are the real, useful effects, and they're free to test right here.
Frequently asked questions
What is black noise?
Mostly a poetic name for silence — or, in technical usage, noise with essentially no energy at most frequencies (silence with the occasional random spike). There is nothing to "play": if you see a 10-hour "black noise" video, it is either silence or very quiet brown noise. If you sleep best in silence, the honest tool is earplugs, not a generator.
What is blue noise good for?
Blue noise emphasizes high frequencies (energy rising ~3 dB per octave) — it sounds like a bright hiss. Almost nobody sleeps to it, but it has real technical uses: audio engineers use it for dithering, and graphics programmers for sampling patterns. As a sleep sound, it usually loses to pink or white within a minute of listening.
Is red noise the same as brown noise?
Yes — "red noise" and "brown noise" are two names for the same ~6 dB-per-octave low-heavy spectrum. "Brown" comes from Brownian motion (Robert Brown, the botanist), and "red" from the optics analogy: deep frequencies are to sound what red is to light.
What is grey noise?
White noise re-shaped to match human hearing sensitivity, so every frequency sounds equally loud to the ear (following an equal-loudness contour) instead of being equally powerful on paper. Conceptually elegant; in practice it sounds like a slightly tilted white noise, and individual hearing varies enough that "equal loudness" is personal anyway.
Which noise color is best for sleep?
The one you notice least — that is the entire job of a masking sound. Statistically, most night-time users end up on brown, pink or green. White wins in environments with sharp sudden noises. Run one night per color with the player, or take our 60-second quiz.