Outlook Visually impaired accessibility

Hi! I have a question that someone has to have the answer to....how do I change my outlook settings so when I highlight text in an email (as if to copy/paste it) so they text turns white and and the highlight section is black?

My friends work computer used to do this automatically, but they gave her a new computer yesterday and all her accessibility settings are gone and no one helped her set them back up.

She can't see black on yellow, which is the default highlight for copy/paste on her new computer. So she can't read what is being highlighted. When we tried to change the actual highlight option to black, thinking it would automatically make the text white, it instead made the selection she wanted to copy/paste look redacted. Also, changing to dark mode didn't work because per her visual impairment she has to read things on a white screen with black lettering.

Someone out here has to know how to fix this because it used to work just fine on her last computer. I'm at a loss.

Any help would be greatly appreciated!!