Hi Dennis,
i haven't done this myself but ill try to explain it...
the DMK will also pick up infrared and ultraviolet light aswell as visible light, for normal imaging you would be using filters that block this light but to do false colour imaging you can use a filter that *only* allows ultraviolet light for example, this will block all visible light and only record the UV wavelength. this can be very useful as i believe this is the only way you can image the cloud detail of Venus.
also a filter that only allows IR through is sometimes used to enhance features on Mars.
theres a good article written by Iceman (Mike) that might be a bit more helpful, see here:
http://www.iceinspace.com.au/index.p...63,468,0,0,1,0
(there are a couple images at the bottom in false colour)