LXQt

Window Theming

If you’d like to have a unified theme for all your GTK2/3/Openbox and Qt4/5 applications and be able to customise them:

Choose gtk in lxqt-config (LXQt System Settings>Appearance);
Install well maintained themes supporting GTK2/3 and Openbox;
Edit manually the theme files to further customise if you like.

For a pure Qt4/5 system you don’t have really an option to choose a preset or customise the default one. You may use the default fusion and wait either for qtcurve or for vitality (bespin developer’s new creation) to have a config tool. Or another generous soul may create a qtconfig-qt5 in the mean time.

Change Icons of Applications and System Settings

The path of icons is saven in .desktop files. For each application you can find their corresponding .desktop files in one of these locations:

/usr/share/applications/
~/.local/share/applications/

open a .desktop file with a text editor with root privileges and look for the following line:

Icon=

insert the path to the icon you want to use after the "=" symbol. a lot of system icons can be found in this location:

/usr/share/icons/

example: if you want to use a flag icon, use this line in the .desktop file:

Icon=/usr/share/icons/gnome/48x48/apps/locale.png