

Pink noise is a random signal with more low-frequency components
than white noise.

If you look at the frequency spectrum of white noise at a frequency
analyzer, you will find that the spectrum power density is flat, which
means that every frequency is present in the noise signal.

Often pink noise is obtained from white noise by integrating of low-pass
filtering a white noise signal. Therefore pink noise contains much more
low-frequency components.

The effect of pink noise is sometimes used to simulate thunder or roaring
animals. An additional low-pass filter with variable cutoff frequency will
explain you why.

Enjoy it.