Should I scan in colour?
Depends what you are scanning. If you are scanning business documents, there is little need to scan in colour unless there is a lot of photos or the content isnt clearly showing up in Black & White mode. B&W saves a lot of disk space. A page of A4 in mono is only around 50K so a 4 drawer filing cabinet would be around 750MB in disk space, saved as say a PDF. Contrast that with colour which would be 24 times bigger.