Theming problem with Niri alongside KDE

[vncnz]

I hope I chose the right section, I need help because I can't get through it...
I have Niri alongside KDE and I'm having same problem with theming. In KDE settings I have the dark theme selected (breeze-dark) but in Niri every KDE app (Dolphin and kCalc, for example) loads with wrong colors, I'm attaching a clarifying screenshot.
With the light theme is all ok.

Thanks a ton!

[YaLTeR]

Since niri uses the gnome portal, you presumably need to set the gnome dark style property in dconf?

[vncnz]

I tried both dconf write /org/gnome/shell/extensions/user-theme/name "'Breeze-Dark'" and gsettings set org.gnome.desktop.interface gtk-theme 'Breeze-Dark' but without effect, it was already set in GTK too.

Firefox is using the correct theme, getting it from GTK config on the fly, KWrite too. KTorrent uses always a light theme. KCalc and Dolphin are unusable with a mix of light and dark theme.

[YaLTeR]

Weird, not sure then. Would have to look at where KDE apps get their theme settings from.

[YaLTeR]

You could try adding a Settings portal override to the KDE portal in niri-portals.conf?

[vncnz]

I need to install xdg-desktop-portal-kde and add org.freedesktop.impl.portal.Settings=xdg-desktop-portal-kde.service in /usr/share/xdg-desktop-portal/niri-portals.conf ? Sorry but I'm not an expert.

[YaLTeR]

If you have KDE then it should already be installed I think? And yeah, something like this if I'm not mistaken. There's also a user home folder override for portals, see man portals.conf

[vncnz]

The package xdg-desktop-portal-kde wasn't installed, anyway I found that Dolphin and KCalc are written with Qt so I have to fix that style and not GTK one. I don't know how KDE manages this this, I'll try to learn how theming works in the near future (coming weeks, I suppose), I don't have much time for now and I installed Nemo anyway.

Than you very much for Niri, I love it!