While you can already invert PDFs using the Minimal Theme, Minimal Theme Settings plugin, and Style Settings plugin, doing so globally inverts PDFs, which while making light PDFs dark, also makes dark ...
$output = (Split-Path $fileName -LeafBase) + "-out.pdf" & "C:\Program Files\gs\gs10.05.0\bin\gswin64.exe" -o $output -sDEVICE=pdfwrite -c "{1 exch sub}{1 exch sub}{1 ...