How can all colours in a PDF be changed to their compliments? So, I mean that a document consisting of black text on a white background would be changed to a document consisting of white text on a black background. Any red colours in a document would be changed to turquoise colours and so on. Is there some standard utility that could be used for this purpose or am I likely to have to contrive some awkward ImageMagick image conversions?
EDIT: Here's a very manual way of doing this using ImageMagick:
convert -density 300 -quality 100 "${fileName}" tmp.png
mogrify -flatten *.png
mogrify -negate *.png
convert *.png "${fileName}"_1.pdf
EDIT: I changed the wording for the purposes of clarity.