Light from the sun is considered white light because it contains all the colors of the spectrum: ROYGBIV. Clear glass shaped into a triangle, called a prism, can bend or refract white light and disperse it into the colored spectrum. The prism bends the white light as it enters and separates as it leaves the prism and red, orange, yellow, green, blue, indigo, and violet colors are spread.

This is the exact way a raindrop works when creating a rainbow. Basically, a raindrop is a liquid form of a prism. Certain atmospheric conditions can also refract light. That refraction results in rainbows that show the same color spectrum. All colors in white light travel at the same speed but have different amounts of energy. When a light beam strikes different material/medium it slows or changes directions. This allows us to see color.

 Light usually travels in straight lines. This does not allow objects to be seen around corners or behind us. Mirrors and other smooth surfaces reflect light. Reflection causes a change in the light path as it bounces off the surface. Water also refracts light, because light travels slower through water than air.