Color us surprised. Plenty of people use apps and ambient sound machines to reduce clamor and improve their sleep — but not all noise is created equal. In fact, new research suggests that a particular type could seriously compromise your slumber. White noise — and all the other color noises, like brown and pink and green — is a steady sound known as broadband noise. Broadband noise is sound that has a bunch of different frequencies, all playing at once. What sets each of the color noises apart