<DataGrid.Resources>
                                    <Style TargetType="{x:Type DataGridRow}">
                                        <Setter Property="Background">
                                        <Setter.Value>
                                            <MultiBinding Converter="{StaticResource RataScad}">
                                                <MultiBinding.Bindings>
                                                    <Binding Path="scadenza" Mode="TwoWay"></Binding>
                                                    <Binding Path="pagato" Mode="TwoWay"></Binding>
                                                </MultiBinding.Bindings>
                                            </MultiBinding>
                                        </Setter.Value>
                                        </Setter>
                                    </Style>
                                </DataGrid.Resources>