Other Online Vision Experiments are available at the Exploratorium website. Online activity available . Each triplet has a red, green, and blue dot. By illuminating different combinations of these dots at varying intensities, the monitor produces a wide range of colors. Red, green, and blue light are considered the primary colors because they can be projected in different combinations to produce all other colors.
Some restaurants have large screen projection monitors on which they broadcast sports events.
By casting beams of red, green and blue light onto a screen these monitors generate enough colors to produce a life-like effect. Now turn on just the red and the blue lights and describe the color produced. Place an object close to the screen and note the color of the two shadows. Repeat with the red and green lights followed by the blue and green lights. Since the object is illuminated from three different locations, it will cast three separate shadows.