Archive of the former Yahoo!Groups mailing list: MOTM

To summarize (in increasing high frequency content order):

Red noise - very low frequency content, almost subaudio, akin to slow
random.

Pink noise - equal energy per octave, sounds like low-Q wind (open
your car windows at 70 mph)

White noise - equal energy per unit bandwidth, sounds higher pitched
like steam.

Blue noise - energy increases with frequency, has the most high
frequency content of all.

You can obtain practical audio approximations of these using white
noise and highpass or lowpass filters, so the terms sound more exotic
than they really are.

Moe