[Gtk-sharp-list] Change Widget Background color

[Adrian Gonzalez Alonso]

Just to give you an overview, I have a splash/login window with a
fixed container and two widgets on it. An image widget that covers the
whole window (logo and some nice gradients) and an entry widget over
it to enter the user and then password (as some linux distribution
does)

The problem is that the entry widget has some white background that
does not fit very well with the image (which is green).
If there anyway to make it transparent or to manually set the color?

I've tried :

entry1.ModifyBg( Gtk.StateType.Normal, new Gdk.Color( 0xff, 0, 0 );

which should set the background to red, this did not happen.

Thanks in advance,

Adrian

mono: 1.2.5