Just as white light contains every color, "white noise" contains every audible frequency. Shift the balance of those frequencies and you get a different color of noise — a different feel, and a different best use. Here's the whole spectrum, plainly, from brightest to deepest and a few oddities at the edges.
The full spectrum at a glance
| Color | Sounds like | Energy sits in | Often used for |
|---|---|---|---|
| White | Bright hiss, TV static | Equal across all frequencies | Masking, tinnitus relief |
| Pink | Steady rain, waterfall | More in the lows | Sleep, deep-sleep research |
| Brown | Deep rumble, heavy surf | Strongest in the lows | Focus, deep calm |
| Green | River, soft waves, breeze | The middle frequencies | Sleep, a nature feel |
| Blue | Bright hiss of steam | More in the highs | Alertness, masking sharp highs |
| Violet | High sizzle, running water | Strongest in the highs | Tinnitus masking, focus |
| Grey | Balanced, even wash | Tuned to equal loudness | The most "neutral" to the ear |
| Black | Near-silence | Little to no sound | Quiet, minimal-sound sleep |
The everyday three
White, pink and brown are the colors you'll actually reach for most, and we cover them in depth in their own white vs pink vs brown guide. In short: white is bright and great at masking; pink is softer, like rain, and has the best sleep research behind it; brown is deep and rumbling, a favourite for focus.
Green: the nature-like newcomer
Green noise emphasises the mid-range, so it sounds like calm nature — a stream or gentle surf — and it's had a huge surge in popularity as a sleep sound. Full details in our green noise explainer and the green vs brown comparison.
The brighter colors: blue and violet
Blue noise is the mirror image of brown — energy pushed into the high frequencies, giving a bright, hissy, lively quality (think steam escaping a pipe). It's more associated with alertness and focus than sleep. Violet noise (sometimes called purple) is an even more extreme high-frequency version, a sharp sizzle. Because it's so high-focused, clinicians sometimes use it to help mask tinnitus — though, importantly, the research on masking tinnitus is mixed, and there's a caution worth knowing (below).
The odd ones: grey and black
Grey noise is white noise re-balanced to match how the human ear actually hears — it's tuned for equal loudness across the spectrum rather than equal energy, so it sounds the most even and neutral to us. Black noise is essentially the sound of near-silence — minimal sound with only the occasional random blip. It's a favourite for people who want quiet rather than a wash of sound.
Pick-by-goal shortcut
- Sleep → pink, brown or green.
- Focus → brown, sometimes blue.
- Masking a noisy room → white or grey.
- Tinnitus → white or violet are common, but read the caution and see a professional.
A word on tinnitus and volume
Colored noise is often suggested for tinnitus, and many people do find it eases the ringing at bedtime. But it's worth knowing that a review in JAMA Otolaryngology–Head & Neck Surgery raised a caution that constantly masking tinnitus with sound could, over time, place strain on the auditory system.1 The evidence is genuinely mixed — so if you're using noise for tinnitus, keep the volume gentle, give your ears quiet breaks, and talk to an audiologist. And whichever color you choose, follow safe-listening limits.
There's no "best" color — only the one your brain stops noticing. The whole spectrum exists so you can find your fit.
Evidence tier: Mixed. White and pink have the most research; the rest are lightly studied and largely preference-driven. Use freely, expect comfort rather than cures. How we rate evidence →
References
- Riedy SM, Smith MG, Rocha S, Basner M. Noise as a sleep aid: a systematic review. Sleep Med Rev. 2021;55:101385.
- Papalambros NA, et al. Acoustic enhancement of sleep slow oscillations in older adults. Front Hum Neurosci. 2017;11:109.