The color wheels are mesmerizing optical glass filters. These are the "VizSim Bright" variant. They appear to reflect in a primary color (red, green, blue) but transmit light in secondary (yellow, cyan, magenta).

Printing on the ribbon cables suggests these were made by EIS Optics, which was assimilated by Materion, who still makes color wheels and other projector components.

The color wheels can be detached from the brackets -- the back unscrews with a pair of needle-nose pliers, or a specialized spanner -- but I did not have the tools to do that yet.