Issue appears mostly with GTK applications (I think Dropbox, XChat and GIMP are all GTK). If I launch them “properly” (e.g. krunner), the programs will use the proper colors and DPI. If I run them from terminal, they’ll show a blatant disregard for the settings.

Pic for illustration:
lel4.png

The issue first appeared when I downgraded from Plasma5, how to fix?