This activity is an online exhibit presented by the Exploratorium. With this activity, you will have fun learning that with just three colors of light (red, blue, and green) they can make over 16 million colors! To do this activity, you should select a background color and then adjust the balance of three colors (red, blue, and green) associated with the circle to match the background. Once the circle disappears into the background, you can check their progress by clicking on the "check color levels" icon. Then to the left, small arrows will appear next to each color column, indicating the amount of each color used.You can continue matching other circle colors to the background color by clicking the "change background color" icon on the bottom right. Note that the color of the center circle may appear to change when they change the background.
Have students research and write a one-page paper as to why, with just three colors of light, millions of colors can be made! They could include in their paper ideas mentioned on the site: such as, comparing light to pigments and the illusion of color change noticed in the circles. This activity could be used as an enhancement to classroom lessons surrounding the visual system or lessons about color.