Bug 433529

This is a sort of usability enhancement I propose here.

On my system I use the default "Breeze" color scheme for nearly all applications, but modified ~/.config/gwenviewrc to make Gwenview use Breeze Dark color scheme (like described here: https://www.reddit.com/r/kde/comments/9ciyqv/kde_how_to_change_specific_app_theme/ ).

I have run it this way for at least a year and I'm really satisfied with this tweak, since viewing images subjectively works better for me when Gwenview uses a dark theme/Breeze Dark (on the other hand I don't like it that much if everything else has a dark color scheme).

Since adding whole color scheme definitions to gwenviewrc is a bit messy, I would like to propose to:

- Either add a setting (regardless if it is enabled or disabled by default) to make Gwenview use a dark color scheme even if a bright color scheme is used globally (if that's feasible).
- Or make it possible to select a color scheme that Gwenview should use instead of the global one (via Gwenview settings and/or gwenviewrc, something like "OverrideColorScheme=Breeze Dark" instead of needing to copy&paste the whole scheme definition). digiKam offers something like this at the "Settings -> Design" submenu.

Kind regards,
Jan