Integrate GTK applications in KDE style

P. I installed the KDE desktop, but my preferred applications: Iceweasel and GIMP look horrible how to fix this?

R. In order your GTK+ 2.x and GTK+ 3.x applications have the same appearance as the native KDE applications you should install the following packages.

– gtk2-engines-oxygen
– gtk3-engines-oxygen
– kde-config-gtk-style

To do this, type the following command in Debian GNU/Linux

sudo apt-get install gtk2-engines-oxygen gtk3-engines-oxygen kde-config-gtk-style

then go:

1. Start Menu
2. Select System Settings (KDE 4) / Settings > System Settings (KDE 5)
3. Select Application Appearance
4. Set the options shown in the figure below

Appearance of GTK + applications in KDE
Appearance of GTK+ applications in KDE

Recommended reading

KDE project