When default light variant is used
I know that in Tweaks one can set to 'prefer dark variant'. But some applications (terminal, video player
audience, the photo viewer
pantheon-photos) are always dark even when the default light variant is used.
Some native applications seem to use dark theming, while the majority do not.
- UPDATE after jena's answer saying dark theming is intended by elementary OS developers for native applications where light theme would not look right: there are also non-native applications that show dark window border, like mpv and Gnome MPV.
When dark variant is used
Also, when 'prefer dark variant' is enabled, another kind of inconsistency appears, namely among the applications that were light-themed in the previous case: some applications use a dark theme in the sense that the upper window border is dark with light buttons while the rest is still light (most non-native applications, and Scratch text editor), while others are fully dark, window border, but also dark toolbar, and dark backgrounds (most native applications, with the exception of Scratch text editor, but also many non-native ones: Pragha music player,
dconf-editor, Sound Juicer etc).
Why the difference?
Is it related to gtk versions?