I think ink and mirrors are kind of fundamentally incompatible. Probably closer to what you're thinking about would be putting a bunch of tiny bandpass filters

I think ink and mirrors are kind of fundamentally incompatible. Probably closer to what you're thinking about would be putting a bunch of tiny bandpass filters infront of a mirror, but in that case you can ditch the mirror entirely and just point the camera through the filter array. A filter array right on-top of the sensor is how (the vast majority) of) CMOS cameras distinguish colour anyway.