如何自定义Flutter Material 3 Switch？解决白色边框修改难题

已将Flutter Material 3 Switch的大部分样式自定义为红色，但仍存在白色边框，找不到对应参数将其修改为红色。查阅Switch类官方文档后发现，文档中两个示例基于Material 2，唯一的Material 3示例未涉及边框修改。

当前Switch组件配置代码如下：

Switch(
  // focusColor: Colors.blue,
  trackColor: MaterialStateProperty.resolveWith(
    (Set<MaterialState> states) {
      if (states.contains(MaterialState.selected)) {
        return Colors.red;
      }
      return Colors.red.withOpacity(.1);
    },
  ),
  overlayColor: MaterialStateProperty.resolveWith(
    (Set<MaterialState> states) {
      if (states.contains(MaterialState.disabled)) {
        return Colors.red;
      }
      return Colors.white.withOpacity(.1);
    },
  ),
  // hoverColor: Colors.green,
  thumbColor: MaterialStateProperty.resolveWith(
    (Set<MaterialState> states) {
      if (states.contains(MaterialState.selected)) {
        return HSLColor.fromColor(Colors.red)
            .withLightness(0.2)
            .toColor();
      }
      return Colors.red;
    },
  ),
  splashRadius: 24,
  // inactiveTrackColor: Colors.pink,
  // activeTrackColor: Colors.green,
  thumbIcon: MaterialStateProperty.resolveWith(
    (Set<MaterialState> states) {
      if (states.contains(MaterialState.selected)) {
        return const Icon(Icons.check, color: Colors.red);
      }
      return null;
    },
  ),
  // activeColor: Colors.lime,
  // inactiveThumbColor: Colors.orange,
  value: _value,
  onChanged: (bool value) => setState(() => _value = !_value),
)

已尝试过代码中注释掉的参数，但均无效。

内容的提问来源于stack exchange，提问作者Alex