No, I'm talking about the Omega/Saunders/LPL 4500-II. It comes with the option of a "B&W module" which is an empty box, a color module or a VCCE module. These modules slide in between the light source and the diffusion chamber. The B&W module really is an empty box. The front of the head (not the module) says "Super Dichroic". It doesn't help that the B&W module is the color module without the guts but with the moldings where the 3 color adjustment displays are in the color head. This is it on B&H:
The description is wrong though (it discusses the two other modules).
But to return to the question: Is there much of a difference between using the same diffused light source with dichroic filtration versus under the lens filters?