Colored Shadows
How many colors can your shadow be?
Several colored light sources create shadows of different colors at the same time. This exhibit vividly demonstrates additive color mixing.
The Science Behind It
The wall is illuminated with red, green, and blue light at the same time. Together, these appear white to us. When you stand in front of the wall, your body blocks some of the colors. A shadow therefore shows the light that is not blocked. Block red → you see cyan (green + blue). Block green → you see magenta (red + blue). Block blue → you see yellow (red + green). If you block two colors, only one remains. If you block all three, the shadow is black. If you block none, it stays white. Three light colors can produce eight visible colors in total. This principle is called additive color mixing and is also used in every screen.
