I frequently use Google Docs for collaborative assignments, and love its ability to show you where other people are typing (and who is doing it) in real time. However, when returning to a document after editing has already been done, it is sometimes difficult to see who has added what. I know it's possible to go back in the revision history, but I would like a way for all edits from each user to appear in a different color. So, if I edit a document, my edits would show up in one color, and remain that color until manually changed otherwise, and likewise with different colors for everyone else editing the document. Does anybody know of a way to do this?