Question

Why clouds appear white?

Answer 1

Clouds appear white because of the scattering of sunlight. White clouds are composed of small water droplets (or sometimes ice crystals, at high altitudes). The droplets in clouds are big compared to the wavelength of light,

size of dust and vapor >$\lambda$

And We know, $S=1/{\lambda }^4$

Hence we see the “color” white, which results when all the colors of the spectrum are mixed together.