You need mono sensor for mono capture. But that is not enough because what really matters is the filter used. For lunar imaging for both cameras (mono and color; where mono would be more optimal) you have to use an IR-passing filter. This can be from red/orange visual filters to Baader IR-Pass or Astronomik ProPlanet 742.
When using with a color ASI120 you ought to remove the built in IR-cut filter or if not - use orange visual filter. The image will be pink-purple. After stacking just change it to shades of grey ;)
