Dark theme not working properly for some PDFs

[Oliver-Haynes]

when trying to apply the firefox theme only the area behind the text changes,but when using the regular dark theme it works fine

[shivaprsd]

Hi @Oliver-Haynes, probably this PDF has a big white image behind the text. Can you attach the PDF, so that I can try to reproduce the issue? Thanks!

[Oliver-Haynes]

Hi @Oliver-Haynes, probably this PDF has a big white image behind the text. Can you attach the PDF, so that I can try to reproduce the issue? Thanks!

https://madasmaths.com/archive/iygb_practice_papers/fp2_practice_papers/fp2_w.pdf
not the same pdf but from the same place

[shivaprsd]

@Oliver-Haynes Yes, the PDF has a big all-white rectangular image (almost covering the page) behind the text (probably to include the vertical watermark on either sides). You can verify this by toggling the Blend Images option in the toolbar (click the ⚙️ icon near the theme name to reveal it), you can see it even in the light theme.

Some PDF apps create PDFs this way, which is sad, and the best we can do is to invert the image. But then it is nearly the same as using the "regular dark theme" (which actually is just inverting the page colours).