The colours describe a spectrum
Naming noise after colours comes from light. Mix every wavelength of light evenly and you get white; distribute sound energy evenly across all frequencies and you get white noise. These are defined spectral properties, not brand names invented by sleep apps.
Human hearing is roughly logarithmic across frequency, so a physically flat spectrum sounds bright and hiss-heavy to us. Think of the static between radio stations, or an untuned analogue television.
How the three behave
Pomodig synthesises all three in the browser rather than streaming files, so they use no bandwidth and loop forever without a seam.
White noise - the strongest mask
Energy is spread evenly across the spectrum, including the range where speech lives. That makes it the most effective at covering conversation, a colleague on a call, or a neighbour's television.
The cost is fatigue. The prominent high end feels harsh after an hour or two, which makes it a poor default for a long study day.
Pink noise - the balanced default
Energy halves with each doubling of frequency, which is why every octave sounds roughly equally loud to us. A great deal of natural sound sits near this distribution, including steady rain and wind.
It is softer than white noise and much easier to tolerate for hours. If you do not know where to start, start here.
Brown noise - deep and heavy
The high end drops away faster still, leaving a low rumble: a waterfall, distant thunder, the cabin of an aircraft. It has become particularly popular among people who describe themselves as easily distracted.
It is the least tiring on the ears and works well before sleep, but it masks speech less effectively than white noise.
Choosing by situation
There is no correct answer, but these are reasonable starting points.
- Conversation or phone calls nearby: white noise, quiet. Layer rain over it if it feels harsh.
- A silent library where sudden sounds startle you: pink noise, very quiet, to flatten the contrast.
- Long coding or writing sessions: brown or pink noise, for lower ear fatigue.
- Lyrics distract you but silence feels wrong: pink noise with a crackling fire layered in.
- Falling asleep: brown noise at low volume, ideally with a timer to shut it off.
Volume matters more than colour
Whichever you pick, the wrong volume undoes it. The target is simple: quiet enough that you stop noticing it is there. If you turn it up until it erases the room, the noise itself has become the distraction.
There is a hearing-safety argument too. If you are wearing earphones for hours, stay well below half volume and give your ears a break every hour or two. If you can play it quietly through speakers instead, that is gentler still.