If you scan in mono you get RGB separations that have more resolution per channel. If you scan in colour you get 1080P luma, but the colour resolution is split up between R-G-B.
It just means that in theory you get more colour detail if you scan each channel separately in mono, but it is extra work as you have to recombine each frame.
Unless you are running some heavy duty gear, I would probably stick with the colour scans, it probably exceeds what is there in this print anyway.