Hazardous chemicals. Use safety goggles.
A plexiglass cylinder is filled with water to which about 700 ml of saturated sodium thiosulfate solution and a beaker of dilute hydrochloric acid are added. After a short time, the water-sodium thiosulfated solution begins to get cloudy. A light is directed through one end of the cylinder. The light scattered from the beam going through the cylinder appears to be blue, while the transmitted light to the other end of the cylinder becomes red. The blue light is scattered more than the red light.