Fill the drinking glass half full of water and place a pencil in the water.

Ask the class if the pencil looks straight or bent.

Explain that the light is bent as it goes through the water, and because the light is bent, it makes the pencil look like it is bent.

Rotate the prism with the point down on the surface of the overhead projector to display color separation on screen or ceiling.

Have the students observe the results. They may speculate about why the light changes color when it passes through a prism.

Hold a short discussion of Newton's observations (see background information).

To help the students understand the difference between reflection and refraction, hold the mirror up in front of the overhead and point out how the light is bounced off of the mirror to the wall or ceiling.

Reflection is when light bounces off an object.

Refraction is when light passes through the object but is bent in the process.

Introduce the students to the filters and gels and how they affect light.

Have them observe the effects of adding red, green, and blue (RGB). Video cameras, TVs, and computer monitors use red, green, and blue lights to create color.

Let the children explore different combinations of the three lights and observe what colors they create.

Help them discover the secondary colors of light (cyan, magenta, and yellow) which result from mixing the primary colors of light (red, green, and blue).

Have the children decide what color of light is blocked to create each colored shadow.

"White light" is created by combining the colors red, green, and blue.

Give the spectra glasses to the children.

Ask, "How are the glasses like the prisms?"

Let the children explore and talk about the ways the glasses change the colors projected on the screen.

The stage lights also called fresnel lights and gels are used in theater and television studios. By overlaying the gelled lights, many different colors are created.

Usually, people are surprised that green and red will make yellow, but the color yellow is between red and green in the visible color spectrum.

The order of the visible spectrum is red, orange, yellow, green, blue, indigo, violet.

A mnemonic that is commonly used is Roy G. Biv.

Centuries ago, in 1665, Sir Isaac Newton realized that sunlight, sometimes called "white light," contains many different colors.

These colors can be refracted through a prism into the visible spectrum. Originally, Newton developed a color wheel based on the primary colors of red, yellow and blue.

This color wheel is still used when mixing colors with paints.

It is sometimes referred to as the psychological color wheel.

Printers use a different color wheel with the primary ink colors cyan, magenta, and yellow, with a black overlay (CMYK).

This is called subtractive primary colors because the white light bounces off the paper, and each layer of ink subtracts or filters out part of the visible spectrum.

We can recreate "white light" with three primary colors of light: red, green, and blue. Red, green, and blue (RGB) are the primary colors used to create the color we see in a television or computer monitor, in video cameras, and other similar technologies.

This is called the additive color wheel because we start in the dark with no light, adding each color.

If all the light waves in the visible spectrum are represented, the light is "white" like sunlight.

The rods and cones in our eyes are sensitive to red, green, and blue as well as light and dark.

We see various colors, depending on the length of the light rays reaching the rod and cones in the back of our eyes, and how our brain interprets the signals.

Physically, red, green, and blue are the basic components of all colors.