Interactive demo

Colors of Noise

Noise gets its color from its spectrum, by analogy with light: white noise has the same power at every frequency, pink and brown noise are dominated by low frequencies, blue and violet noise by high ones.

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Start with a low volume, blue and violet noise sound sharp. The dashed line is the ideal slope of the selected color.

Controls

Sound

Legend

  • White
  • Pink
  • Brown
  • Blue
  • Violet

Noise types compared

NoiseOutputBuilt fromWork per sampleSmooth
Value NoiseScalar fieldRandom values on a grid4 grid pointsYes
Perlin NoiseScalar fieldRandom gradients on a grid4 grid pointsYes
Simplex NoiseScalar fieldGradients on a triangle grid3 cornersYes
Worley NoiseScalar fieldRandom feature points9 to 25 cellsNo
Blue NoisePoint setRandom candidates around existing pointsUp to 30 tries per point–
Fractal NoiseScalar fieldOctaves of a base noise1 base noise per octaveYes
Diamond-SquareHeightmapDisplaced midpoints of a grid4 neighbors per pointNo
Colors of Noise this pageSignal or imageWhite noise filtered by frequency1 FFT for all samples–
Domain WarpingScalar fieldFractal noise at warped positionsUp to 5 fractal noisesYes
Curl NoiseVector fieldDerivatives of a noise field4 noise samplesYes
Noise Terrain GeneratorHeightmapStacked noise layersLayers × octaves–

1. What the color means

The spectrum shows how much power a signal has at each frequency. On a log–log scale, colored noise is a straight line: the power is proportional to the frequency raised to a power β, with β = 0 for white, −1 for pink, −2 for brown, +1 for blue and +2 for violet noise.

2. Shaping the spectrum

All five start as the same white noise. A fast Fourier transform (FFT) splits it into frequencies, every frequency is scaled so that its power follows the slope, and the inverse transform turns it back into a signal. The image is made the same way in 2D.

3. Where they are used

Pink noise sounds balanced to our ears and is used to test loudspeakers and rooms. Brown noise, named after Brownian motion rather than the color, rumbles like a distant waterfall. Blue noise has no clumps, which makes it ideal for dithering and for spreading out sample points.