This model lets users interactively explore how the human eye interprets colors for various combinations of red, green, and blue light. The first simulation features three monochromatic lights in red, blue, and green. Use the slider to control the intensity of each color to see what colors will be perceived by human vision. The second simulation lets users apply a filter to white light or to any wavelength of color and examine how the filter determines what colors pass through to the eyes. Note: This resource has been rewritten to HTML5, making it more versatile for use in all major browsers, mobile devices, and tablets.

This resource is part of a large collection of free-access simulations by the Physics Education Technology Project (PhET) for use in STEM education from K-12 through graduate level. The simulations were designed using principles based on physics education research and refined based on student interviews and classroom testing.