PIRA: 6F10.10


  • Three colored lights (blue, red, green)
  • screen or wall
  • plug strip


  1. Turn on lights and aim the beams at the same spot on the wall or screen. You should see white light resulting from the combination of three lights.
  2. If light is not quite white, adjust each light intensity or vary the distance of the individual lights from the screen.
  3.  Put your hand, meter stick, or some object in white light area and observe colored shadows. Each shadow is composed of two primaries. For example, if red is blocked the shadow is a combination of blue and green