GTK icons missing using a window manager

If you’re using a window manager, such as awesome or goomwwm, instead of a desktop environment, such as GNOME or XFCE, then you might have the issue of some GTK applications not looking quite right, a problem I had was with missing icons.

Before and after:

GTK Before and After

List all available icons themes:

ls ~/.icons/ /usr/share/icons/

You need to append the line, gtk-icon-theme-name = "-insert-theme-name-", to /etc/gtk-2.0/gtkrc or ~/.gtkrc-2.0.

echo "gtk-icon-theme-name = \"Humanity\"" >> /etc/gtk-2.0/gtkrc

The above command globally sets the theme to Humanity. The command is appended if the file exists, and creates it if not.