Different colors of noise can help improve focus, sleep, and relaxation:

White noise is effective for blocking out distractions and can help with sleep and tinnitus.

Pink noise, with more power in lower frequencies, can aid in falling asleep and improving memory retention.

Brown noise, lower in tone and intensity, is helpful for masking unwanted sounds and can enhance concentration and REM sleep.

Green noise, though not officially recognized, can have a calming effect on the nervous system and may benefit those with racing thoughts and anxiety.

https://www.washingtonpost.com/home/2023/10/09/white-noise-color-sounds-brown-pink/