When tracking changes, is there a maximum number of reviewers you can have in
Word 2007? Can you control/limit it somehow?
Word will track an unlimited number of reviewers, in the sense of attaching each
reviewer's name/initials to the changes they make. If you're displaying the
changes with colors set to "By Author", there are only 16 colors in the palette
(one of them being the useless white), and after that number of reviewers the
colors will start to repeat the cycle.
There is no way to specify which reviewer gets which color; and viewing the same
document on a different copy of Word will often reassign the colors to reviewers
in a different order.
The only way to 'limit' the number of reviewers is to prevent more people from
editing the document.