I am using Android version.
Often I found the "Color Document" has a better result for the documents or receipts I captured. However, the automatical capture for the document in my case is always "Document" even my document has very distinct color other than b/w. And not mention those "colored" documents were often identified as photos.
It seems that there is a lot of room for improvement here for the auto-capture mode. But I would suggest that at least to make the "Color Document" more useful as it usually produces a better result. It shouldn't be too hard to add an option in the APP settings states "Always Use Color Document for Capturing Document" when the captured object is identified as a document.