The type of extra equipment is determined by the manner in which the colour information is obtained. If a mechanical shutter is used, then the complexity of the control of this depends on the video camera used. With the recommended Cohu cameras, a simply AC synchronous motor is all that is required. This is necessary because the frame grabber card used by DigImage is only able to digitise grey-scale images. The Multiplexer is essentially an electronic switch with eight possible inputs, and one output.
Many decoders have the sync signal on only the green component.
There are a number of decoders available. Your local video supplier should be able to provide some details. The first issue is horizontal resolution. Colour scenes will have a resolution somewhere between these limits. The alternative method of obtaining colour, used in more expensive cameras, is to use a prism to split the incoming light into its components and have separate CCD chips for each of them.