Added in a template binding to the background property in the MaterialDesignDatePicker, this now makes it so when setting Background on a datepicker it will reflect the change. (#1721)

Author: ColossalMoose

MaterialDesignThemes.Wpf/Themes/MaterialDesignTheme.DatePicker.xaml

@@ -375,6 +375,7 @@
                         <DatePickerTextBox x:Name="PART_TextBox"
                                            Grid.Column="0"
                                            Focusable="{TemplateBinding Focusable}"
+                                           Background="{TemplateBinding Background}"
                                            Grid.Row="0"
                                            Padding="0,0,8,0"
                                            VerticalContentAlignment="Center"