Better way is to scan full resolution jpeg compressed an let the application work on the pages afterwards to determine if each page should be converted to greyscale, black and white and so on, and to reduce resoluton on the greyscale and color pages if required. Even better is to use like PDF/A Compact which compressed colorpage way down, if not much data on them it is nearly like black and white scans. Then you are not dependent on specific scanners supporting multiimage scans, there is alos difference in functionallity and many limitations in the scanners if “mulit-image” is enable. Thrust me, stay away from it for a long time yet.