Problem: QT4 applications do not inherit the GTK theme (when using XFCE for example)
Solution: Read AlienBob’s blog regularly :) So, open
/etc/profile.d/qt4.sh and add the following lines on some empty rows:
GTK2_RC_FILES="$HOME/.gtkrc-2.0:/etc/gtk-2.0/gtkrc" export GTK2_RC_FILES
Now log your user out and in and launch
qtconfig if necessary.