Refraction

Refraction is the bending of light through a substance. Different substances bend light at different angles. White light is made up of a full spectrum of colors. Each color has a different wavelength, and bends at a different angle. This is the same effect that produces rainbows in the atmosphere. The most common illustration of this is a glass prism as seen here.

The colors of the spectrum can be remembered easily with the acronym ROYGBV (pronounced: roy-gee-biv)

ROYGBV
Red	Orange	Yellow	Green	Blue	Violet