Bug#717130: I found a solution

[Natanael Arndt]

I had to install "gtk2-engines-pixbuf" to get the GTK2 apps to use the
default gnome theme (in my case adwaita). "gtk2-engines-pixbuf" is also
recommended by "gnome-themes-standard".

I don't know if somehow debian should automatically install
gtk2-engines-pixbuf if gnome-themes-standard is upgraded to achieve the
same behavior as before.

I think the issue can be closed.

Kind regards
Nate