“Monochrome” cameras see, as you guessed, brightness only, no matter what colour or mix of colours the light is.
Whether you use a camera that can or cannot record colours does not really matter. The image will be recorded as the camera sees it. If one only processes B&W (greyscale) material, not recording colours will provide higher resolution.
@Alain_Oguse is taking the long road to get what he wants. Whether that is the same for you is something that you can either find out by trying to replicate the gear modifications Try a green LED lamp in your other Beseler and point your camera upwards like so: Let's see your DSLR film scanning setup! - #35 by Digitizer
(please note that the picture only shows the general idea. In reality, the lamp house is much closer to the camera and the enlarger’s bellows surrounds the lens.
Quick Test: Scan taken with green backlight from an iPad as seen in Lr at 300%
