Bug 417909

Summary:	RFE: Text and page background - dark themed
Product:	[Applications] okular	Reporter:	pierrelud
Component:	general	Assignee:	Okular developers <okular-devel>
Status:	RESOLVED WORKSFORME
Severity:	wishlist	CC:	kwon-young.choi
Priority:	NOR
Version First Reported In:	1.6.3
Target Milestone:	---
Platform:	openSUSE
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:

Description pierrelud 2020-02-20 08:26:36 UTC

I'm reading a lot of pages using a notebook and with black text on a white page it uses a lot of battery power. Now I know it is the amount of white the PC have to lit up on the LCD that draws this power.

So this is what I'm wondering if Okular could be enhanced so that text and page colour can be chosen? Not sure if PDFs would allow this, but as analogy I'm thinking about the profiles for Appearance of Color Scheme & Background used in KDE Konsole and how one can change these that suites a user's taste.

Now choosing an options for me like Dark Pastels from Konsole for Okular pages would be super and my time on battery power greatly extended. 

Please consider.
Pierre

Comment 1 Kwon-Young Choi 2020-02-20 13:38:03 UTC

Hi,

Just an okular user here, but I think there is already an option to change the background and foreground color in okular.

Go to "Settings" -> Configure Okular -> "Accessibility".
Then, tick the "Change colors" box and select "Change Dark & Light Colors" menu item in "Color mode".
This will allow you to change the "Dark color" (background) and "Light color" (foreground).

However, that settings comes with the warning: "Warning: these options can badly affect drawing speed".
I suppose that rendering a pdf with other colors involves additional processing which could impact your battery life so I'm not sure if this is a good solution.

Best regards,
Kwon-Young Choi

Comment 2 Christoph Feck 2020-03-19 16:46:44 UTC

Right, changing colors requires post-processing, but the option is already there.