PDF in Firefox: This page is protected by browser

[mamolas]

Uh, oh yeah PDF is for Firefox disabled as they already don't allow us to style any .pdf

Originally posted by @Gusted in #2856 (comment)

The issue is 2 years old, is the new Firefox also restricted to invert PDFs with dark reader? Is there any tweak at about:config to allow this important feature?

[Gusted]

The page is protected, no exceptions for addons.

[luo-chuan]

If you use Firefox, you can edit userContent.css like this:

@media (prefers-color-scheme: dark){
  .pdfViewer{filter: invert(1) hue-rotate(180deg);}
}

If you use Chrome or Edge, install the extention "PDF Reader", then edit the extention option like this:

html[data-theme*="dark"] .pdfViewer{
  filter: invert(1) hue-rotate(180deg);
}

[mamolas]

As a workaround I have a bookmark with the following content:

javascript:(function(){var el = typeof viewer !== 'undefined' ? viewer : document.body; el.style.filter = 'grayscale(1) invert(1) sepia(1) contrast(75%)';})()

When I require to invert a PDF I click the bookmark and it works, although I think it could be embedded in the extension somehow.