[Gtk-sharp-list] Changing the background and text color of a Gtk.Entry

[Agro Rachmatullah]

Is it possible to change the background and text color of a Gtk.Entry?
If so, how?

My intention is to make the text of a Entry red if the user enters an
invalid input (for example "foo" on an Entry that expects an integer).

(From hunting in Monodoc, it seems that it has to be something related
to Gtk.Entry.Style. However the documentation is very minimal on that
regard so I haven't made it work)

Thanks a lot.