flutter_datetime_pickerの上部の色を変える

flutter_datetime_picker | Flutter Package

lib/flutter_datetime_picker.dart

のなかの

  Widget _renderPickerView(DatePickerTheme theme) {
    Widget itemView = _renderItemView(theme);
    if (widget.route.showTitleActions) {
      return Column(
        children: <Widget>[
          Stack(
           children: <Widget>[
             // これ追加
             Container(
               color: Colors.red,
               height: theme.titleHeight,
             ),
             _renderTitleActionsView(theme),
                     ],
          ),
          itemView,
        ],
      );
    }
    return itemView;
  }

ここはコメントアウトしておく色が消えるため

  // Title View
  Widget _renderTitleActionsView(DatePickerTheme theme) {
    String done = _localeDone();
    String cancel = _localeCancel();

    return Container(
      height: theme.titleHeight,
//      decoration: BoxDecoration(color: theme.backgroundColor ?? Colors.white),