Gtk3: background color of gtkcombobox popup trough css

[Roberto_Fortunato]

Is there a way to change background color of popup list item windows in a GtkComboBox using css?
I try
combobox>window.popup cellview{
color: Blue;
background: Green
}

but the result is in attached img. I want all back space green. Haw can I do? Thanks

[Roberto_Fortunato]

Sorry, I solved. I add to css

combobox>window.popup *{
background: Green;
}