Office ignores the Windows theme settings. As far as I know, there is nothing you can do about it. Reinstalling certainly will not help.
Microsoft Word MVP
That was a brilliant idea, unfortunately it was not the problem (but
it seems like that might be a problem for others). I am nearing a
point of a reinstall, but I would really like to avoid that (since I'd
have to deal with corporate IT and down time).
To elaborate a little more on the situation as well:
This is not only effecting word, it is actually all of office. On
outlook, the highlight color when I click on a message is correct (to
the windows theme), but when I highlight text in the actual body it
does the pure black highlight.