How Does a Prism Produce Colors?
A prism is a piece of glass or other see-through material that has several flat sides, called faces. Many prisms have three long faces in between two triangle-shaped ends. However, prisms can be made in many forms and shapes. We use prisms to bend light.
When we shine a beam of sunlight through a triangular piece of glass called a “prism,” the light emerges in a band of colors. Sunlight is a mixture of all the colors in the rainbow: red, orange, yellow, green, blue, indigo, and violet.
When sunlight passes through a prism, the different colors are refracted (bent) from their straight paths. Violet is bent the most, and it appears at the bottom of the band of colors. Red is bent the least, so it is on top. The other colors fall in between.
Instead of seeing just white, we see sunlight separated into all its different colors. This happens because each color has a particular wavelength and each wavelength bends at a different angle.