Technology bleg (unlimited badges available for helpful answers)

I’m being driven nuts by the following laptop gremlin:

I have a MacBook Pro and a Word document program (I don’t know which iteration).

For months now, my documents in Wprd randomly — it seems random anyway — switch from the standard white background with black lettering to a black background with white lettering. Then it randomly switches back again, usually after a few hours.

How can I stop this, or at least figure out how to manually switch it back to the standard format whenever it happens?

I’ve talked to IT repeatedly and they can’t seem to figure out what’s going on. Do I need to just have a new version of Word installed? (I don’t know how to do this either of course).

Any and all suggestions welcome.