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The three primary colors of light (red, green, and blue) are used to make millions of colors in digital pictures.

Investigation: Making Color with Light

We spend years in elementary school learning how to mix paints to create a desired color. Mixing all of the paints together made a dark color–black, dark brown, dark gray. Yet this doesn't happen with colors of light. A rainbow of colors of light makes white light. Proof? A beam of white sunlight passing through a prism creates a rainbow of color.

A digital image is made up of millions of colored light intensity measurements. The colors? Red, green, and blue. This investigation has a series of activities to help you get a working knowledge of how intensities of red, green, and blue light may be combined to make millions of colors.

See example of a color space using red, green, and blue light.

The three primary colors for print materials are yellow. magenta, cyan -- The inverted primary colors.

Activities to Explore Colors:

Dueling Light Beams – Low cost way to mix beams of colored light—requires no software.

The following activities require ColorBasics,
part of  Digital Earth Watch software:

Compare Colors: Compare the colors produced by mixing colored light and colored paint.

Movies illustrating the basics of mixing paints and mixing light. Created by Marion Tomusiak from the Museum of Science, Boston.

Naming Colors

Movie illustrating effect of mixing color intensities. Created by Marion Tomusiak from the Museum of Science, Boston.

Make Colors — Prediction — This activity is also found under Challenges: Three Color Challenge.
Play with Colors: Challenge your skill at identifying the red, green, and blue contributions in randomly generated colors. Play against a friend or the computer.

Make Colors Reference Chart

Test Yourself: Test your skill at identifying the primary color contributions in randomly generated colors.