The color images we see are made by combining three kinds of light: red, green, and blue. These three colors are called the primary colors of light.

When the red, green, and blue images overlap perfectly on a wall, they blend into one complete color picture. This is the same principle used by computer screens, mobile phone displays, and even astronomical image processing. Try it yourself to experience the magic of light and shadow, and understand how color is created through the cooperation of science and our eyes.

Step 1: Choose a slide and insert it into the light slot to decide the pattern projected by that color of light.
Step 2: Each light source can be turned on or off separately. Viewers can freely observe how different color combinations appear on the wall.
Step 3: When all three colored lights are projected together and overlap on the white wall behind, the original black-and-white patterns combine into one complete color image.