GTK+ in Kubuntu apps look bad

I have installed Evolution email client on Kubuntu 11.10 and it's not so cute as expected.

Eclipse also looks bad. I have the GTK+ Appearance plugin in KDE System Settings and already tried QTCurve and Oxygen option, no help. When the GTK+ skin was working, this appearance still showed when I ran an application as root.

Tried:

sudo apt-get install oxygen-molecule gtk2-engines-oxygen

There is a problem with KDE/GTK relation. How can I solve it?

Make sure you have the following packages installed (they should have been installed by kubuntu-desktop, but may have gotten missed):

sudo apt-get install gtk2-engines-oxygen kde-config-gtk

Then go to the KDE Control centre and make sure that the checkbox for using KDE themes in GTK apps is checked.

Evolution probably uses GTK3 while the instructions are valid only for GTK2.

I'm not sure what is the policy of AskUbuntu on external links, but this one provides a solution for GTK3:

http://maketecheasier.com/make-gtk3-apps-look-presentable-in-kde4/2012/01/04

Here is the latest gtk config tool that allows easy customization of GTK2 + GTK3 under KDE

It will likely become official tool in next KDE version.

I accidentally found the right answer here

UPDATE

Old question with old answers, but maybe still interesting - and appearing in internet searches anyway. So, for the record:

In KDE/Plasma5, there are GTK settings in the System Settings, Application Style: