I don't know if this has been asked before, but I couldn't find it anywhere.

My KDE theme is the default bundled Oxygen, and for GTK apps I use the default bundled oxygen-gtk, and all works well. However, whenever I start a gui app from a virtual terminal (after `export DISPLAY=:0`), the app launches with the wrong theme. KDE/Qt apps launch with the Plastique theme (however opening qtconfig and changing "Desktop Settings (Default)" to "Oxygen" fixes this). GTK apps launch with some weird dark green theme I didn't know I even had installed. For both KDE/Qt and Oxygen apps, the cursor theme changes to a GNOME-style cursor theme.

All this isn't too much of a problem for individual apps, but sometimes I have to use a vt to restart compiz (0.9.4) after crashing. After I restart compiz, every single app I launch, whether I click an icon or type it into KRunner, launch using the wrong theme. Somehow, the app is not detecting the default theme or detecting it incorrectly. Does anyone have any idea why this happens, or hos it can be fixed?

This is likely a result of the same environment variables not being set exactly. I would recommend adding an autostart script which writes out the environment variables present in the full session, then source that prior to launching applications.

You can execute "env" to get the output of the environment in a script sourceable format.