Retinal cells are arranged in a blue-noise pattern, which a number of studies have shown yields good visual resolution. Violet noise is, similarly, like an inverted version of brownian noise.

While green noise has long been my favorite, I may have discovered a new contender while writing this article: blue noise. "Blue noise is the highest frequency of these sound profiles," explains Shah.

Blue noise is best for: Those who can't hear high-pitched sounds very well. Try it: Because blue noise is harsher than the other colors, not many manufacturers include it in basic sleep sound ...

But there are different varieties of noise—patterns within that randomness. When a cat makes that “sss” sound, zillions of air molecules create sound across a broad range of frequencies.