To most people noise might just be noise, but in the audio world there’s more than one type of noise. The various types are named after colors, such as white and pink. According to Wikipedia, the color names for these different types of sounds are derived from a loose analogy between the spectrum of frequencies of sound wave present in the sound and the equivalent spectrum of light wave frequencies. That is, if the sound wave pattern of “blue noise” were translated into light waves, the resulting light would be blue, and so on.
The rest of this article (with a lot of technical explanations) can be found on this Wikipedia page.
The commonly accepted colors are white, pink, blue, brown, purple and grey. Sometimes the names differ, and some wants to add other colors to the list as well.