public static Gdk.Pixbuf DesaturateIcon(Gdk.Pixbuf source)
{
Gdk.Pixbuf dest = new Gdk.Pixbuf (source.Colorspace, source.HasAlpha, source.BitsPerSample, source.Width, source.Height);
dest.Fill (0);
source.SaturateAndPixelate (dest, 0, false);
return dest;
}