Gtk using ugly theme in KDE 4.8.1 on Ubuntu 11.10 OneiricSun 25 March 2012 by Frank Lazzarini
I lately updated my laptop with the latest packages and I've got KDE 4.8.1 from the ppa. To my surprise all the gtk apps that I have installed look terrible, with the standard GTK look, apps like firefox/pidgin and so on. The default theme look was change from oxygen to clearlooks, which is the default in GTK2. I knew there was a little app called gtk-theme-switch2 to change the default look of gtk, which you have to install. So a simple apt-get install got me the thing and I changed the gtk theme to the gtk oxygen theme which looks just about awesome on Kde! If you experiencing the same thing, here is how you fix it.
sudo apt-get install gtk-theme-switch gtk2-engines-oxygen
Then start the it up and select oxygen-gtk and voila!