In a lot of dialogues, but not all (Firefox File > Open for example), the Cancel button is the right-most one, with the Ok button next to it.



Which part of the theming is responsible for the button layout? What do I change to get some different layouts (Ok button on the right)?

I'd also like better contrast for the focused buttons. I've noticed some Application style themes provide good contrast on hover, but not on pure focused state (keyboard users). So I'd like to be able to improve that too.

How is that controlled? It would also be helpful if you could point me to any tutorials about how to change it, create my own theme or similar.

For the button order, if I understand correctly that's a GTK vs. Qt thing. As I recall that used to be configurable in the GTK (theme) settings, but I think that was in a previous iteration of the settings (back in Plasma 4). I don't know how much controll the gtk (or qt) theme has on the button order to be able to enforce a specific direction. That might be something worth bringing up in the Visual Design Group in phabricator.

For improving the contrast, that is something controlled directly by the GTK and Qt themes. Again, bring up your ideas with the Visual Design group and they can offer assistance on how to get started and feedback on the suggestions.

Thank you @airdrik, I've enquired further on the VDG on KDE Phabricator.