Changing background color doesn't always succeed.

[avada]

Some stuff remains white for some reason.
Here's sample book:

childrens-literature.7z

(157.18 KiB) Downloaded 12 times

From here*: https://github.com/IDPF/epub3-samples/releases

I particularly notice it with pdf conversions of newer versions of calibre.
Converted with old calibre, renders fine:

Children's Literature - Charles Madison Curry - old Calibre.pdf

(868.76 KiB) Downloaded 14 times

With newer Calibre, some parts remain white:

Children's Literature_ A Textbo - Charles Madison Curry - newer Calibre.pdf

(2.09 MiB) Downloaded 14 times

Pictures:
Good:

Bad:

(The formatting is borked on the new conversion, but that's beside the point. It's the colors that matter.)

*The URL tag is completely broken on this forum. It's inserted as plaintext.

[Tracker Supp-Stefan]

Hello avada,

There is a "Path" object on that page - which remains white even when the colour overrides are turned on:

If you remove that path - the whole content is coloured correctly:

Kind regards,
Stefan

[avada]

Hello avada,

There is a "Path" object on that page - which remains white even when the colour overrides are turned on:
image.png

If you remove that path - the whole content is coloured correctly:
image(1).png

Kind regards,
Stefan

No idea what a path object is. What is it used for?
Why does the recoloring feature break because of it?

[TrackerSupp-Daniel]

Hello, avada

A "path" object is essentially any graphical base content element in a PDF that is not defined as "text" or an "image". This is usually the lines that make up tables, or the fancy symbols you may see in an engineering graphic, but in some cases, they can also act as a "background" object, simply being a large base content rectangle.

In short, the reason that adding the background color you want is not working here, is because this object is non-transparent, and is in the way of whatever background you try to set. You can select and remove this object with the "edit" tool, by clicking that area on the page, or by opening the "content" pane, shown in Stefan's screenshot, which can be opened with the "options" menu in the bottom left corner of the application.

Kind regards,

[avada]

Hello avada,

There is a "Path" object on that page - which remains white even when the colour overrides are turned on:

kép.png (72.03 KiB) Viewed 311 times

If you remove that path - the whole content is coloured correctly:
image(1).png

Kind regards,
Stefan

How do you bring this content view up? (EDIT: found it) (I never used editing features) Since then I ran into multiple files that wasn't recolored properly.

[avada]

Hello, avada

A "path" object is essentially any graphical base content element in a PDF that is not defined as "text" or an "image". This is usually the lines that make up tables, or the fancy symbols you may see in an engineering graphic, but in some cases, they can also act as a "background" object, simply being a large base content rectangle.

In short, the reason that adding the background color you want is not working here, is because this object is non-transparent, and is in the way of whatever background you try to set. You can select and remove this object with the "edit" tool, by clicking that area on the page, or by opening the "content" pane, shown in Stefan's screenshot, which can be opened with the "options" menu in the bottom left corner of the application.

Kind regards,

It seems like this working is erroneous. It looks like if a path or whatever is a background its should be recolored as well.

I tried with two other PDF viewers I know of that can change background text. Foxit and SumatraPDF. And both recolored these documents fine.

[TrackerSupp-Daniel]

Hello, avada

Our background color feature explicitly follows the PDF specification, which is stated only to add a background object of the defined color, behind all other base content. We do not make any assumptions about other potentially "less useful" base content, nor do we remove or obscure these items, unlike some of our competitors. That is their decision to make, but that is not how our feature is intended to work at this time.

Kind regards,