Color wheel (optics)

An 1895 mechanical color wheel, used for experiments with color vision.

A mechanical four-petal RGBW color wheel inside a 1998 DLP video projector.

For the "planar circular chart" with a spectrum of colors, see colour wheel.

A color wheel or other switch for changing a projected hue (e.g., for an optical display) is a device that uses different optics filters within a light beam. Common usage includes continuously-rotating wheels for seasonal home displays (e.g., at Christmas) and controllable color wheels for a particular instrument (e.g., SeaChanger Color Engine for stage lighting), while non-wheel devices include scrollers and semaphore types with lever arms (e.g., on the 1897-1917 Grand Army Plaza fountain).

A color wheel lamp, c. 1960, utilized for decorative purposes, in the collection of The Children's Museum of Indianapolis.