Protecting Cells In Shared Workbook

I have a shared workbook is it at all possible to leave the cells unprotected so a user can enter data but prevent cells from being formated

for instance someone on night shift with nothing better to do has decided that black text on a white background is boring and changes it frequently to a rainbow of colors. and text types
it is making a well laid out and good sheet look like something a child has done
I would pursue this down a discipline line but it has proved impossible to nail down the culprit from the many users