Hello
I'm using a few KDE applications with Budgie but I'm having a few issues with themes.
As far as I understand the default behaviour when a KDE apps is in a gtk based DE is to try to mimic the current GTK_2_ theme, which is... suboptimal, although I'm sure my theme is at fault (not using the default one).

The question is, is there a way to better control the appearance of KDE applications from Budgie? I don't expect a graphical way, but at least a config file to change or a command to run?

You could try QGnomePlatform. You'd have to build from source, but it may fit the bill.
Also see discussion on this exact topic here on KDE Invent from a few months ago. Our very own Mr. Strobl posted there as well for BoB.

    Brucehankins
    I'l be honest, I though QGnomePlatform was the GTK2 imitation thing.
    Still, from what I read on the dev tracker compiling it on my own would be a pain, since it would need to be recompiled at each KDE update

      I personally wouldn't port any packages that start with K into Budgie. But that's just me. Anyways, you'll see🙂.

        Lucien_Lachance
        This might work, but it's ignoring the palette option. Maybe after a reload it will be better.

        However, it also decided to arbitrarily override a global config (~/.config/fontconfig/font.conf) without warning, so anyone know if we are supposed to have one by default?

          brent
          Eh, sometimes Okular is better than Evince, while KcacheGrind has not GTK equivalent.
          That, and I wanted to try Konsole

            elfprince I tear them all out by hand and when its time to update some of them sneak back in. especially Kwallet which infuriates me. K packages spawn like Tribbles.

                elfprince eopkg info kdeapp. to check deps. 9 times out of 10 it's an app I tried on a whim, unknowing, and forgot to uninstall, or sometimes they are k-orphans.