Question

how does the color of the scattered light depend on the size of the colloidal particles

Answer 1

In case of colloids scattering of light by the particles is observed under ultramicroscope. A colloidal solution is a heterogeneous mixture in which the solute particles of around 1-100 nm in size are dispersed in the solvent. Due to their large size they can scatter light. The colour having shorter wavelength is scattered much more than the colours having longer wavelength.