As a side note, ZoomText color enhancements include a number of high contrast options that fall broadly under the "inverse" universe, but that use something other than white for the text.
When possible, if all the client has had available is a straight black/white reversal, I like to sit with them and go through the various Color Enhancements as they often find that one of the ones available is much easier for them to see than a straight black/white reversal.
Brian - Windows 10 Home, 64-Bit, Version 1803, Build 17134
A great deal of intelligence can be invested in ignorance when the need for illusion is deep.
~ Saul Bellow, To Jerusalem and Back