You're probably not going to like my answer. First, if you can remember what
everything was supposed to look like and how it was all supposed to be
formatted, then a visual examination may reveal it to you by its absence.
The alternative is almost as bad and requires some memory effort also. You
could open the workbook and remove all formatting (choose all cells on each
sheet, used Edit | Clear | Format) and starting from scratch. But that is
likely to produce undesired results, especially with formatted dates.
The problem is that you aren't given a chance to open the workbook with the
guilty formats present so you can make any kind of comparison. It seems to
be one of those questions whose answer is "you can't get there from here".
Going to Excel Help and search for Excel Specifications and Limits and
examining that topic may give you some clues - it tells about the limits for
number of cell formats, colors, and similar things. Perhaps one of those
will ring a bell - like "oh, Excel can only have 4000 cell formats - and I'm
guessing I've probably formatted twice that many individual cells" , but
again that's a very uncertain situation.
I wish I could offer more help. I waited for someone else who might have
had a better answer to chime in here before posting my rather gloomy view of
things. But I'm not all knowing, so perhaps someone else will come along and
come up with a better idea.
