This technique of using different filters on top of a monochromatic sensor is also used in astrophotography, it helps with image resolution. You want as much pi

This technique of using different filters on top of a monochromatic sensor is also used in astrophotography, it helps with image resolution. You want as much pixels per inch as possible so instead of placing multiple narrow band receptors in your sensor you use a single wide band receptor as your pixel and place a filter in front of the camera, for a RGB camera for example you triple the total number of sensors by doing this.