PDF contains a lot of white text, how to make it black (partial ghostscript solution already) -

gs -o res.pdf -sdevice=pdfwrite -c "/osetcolor {/setcolor} bind def /setcolor {pop [0 0 0] osetcolor} def" -f input.pdf 

this changes tables have white borders, (which step in right direction) i'd turn white font black.

these big pdfs pdfedit no. said, above partial solution.

the font white, background white, default colours (it's black colour scheme) on machine made on meant wasn't known author. swap wont work.

i converted document post-script , used function (not sure called) turn black, worked, wrote in answer different question of mine similar title.