White noise stands for a noise in a certain frequency range with a constant power density spectrum. The noise is similar to TV noise, air conditioners or fans. It helps to drown out ambient noise, which makes it useful for falling asleep, tinnitus and concentration.
Pink noise is a random sequence of sounds whose amplitude decreases with increasing frequency. Raindrops, wind or rustling leaves show similar frequencies to Pink Noise. It can help to increase a person's ability to concentrate and improve deep sleep. Consequently it is also relevant when putting babies into a deep sleep.
Brown Noise (also called Red Noise) refers to a sequence of sounds with a low frequency. For example, thunderstorms, rainstorms, or even shouting produce very similar frequencies. Brown noise helps to block out disturbing noises and can have a relaxing effect on headaches, migraines and stress.