When the visible light encounters scattered particles in a colloid-like say dust in air or water light is reflected off of particles that are slightly below or near the size of a wavelength of light. Depending on how much light a particular material absorbs, a different color is emitted. Shorter wavelengths of light tend to be scattered more than longer wavelengths.

(1) The concept is determining the strength of concentrations (Nephelometer)

(2) The headlights of vehicles work on the principle of Tyndall effect

(3) Sunlight visible in dense forest or blue color of the sky is also an example/application of this effect