GroupButtonOptions doesn't seem to work

[Bour1cha]

Hi everyone , can someone explain to me why the colors won't change in options: GroupButtonOptions please ?
i can't see any error

Container(
height: 200,
child: SingleChildScrollView(
child: GroupButton(
controller: _radioController,
isRadio: true,
options: GroupButtonOptions(
selectedBorderColor: lightBlueTheme,
selectedColor: lightBlueTheme,
groupingType: GroupingType.column),
buttons: _radioButtons,
buttonIndexedBuilder: (selected, index, context) {
return Padding(
padding: const EdgeInsets.only(top: 8.0),
child: Container(
decoration: BoxDecoration(
borderRadius: BorderRadius.circular(8.0),
color: backgroundTile,
),
child: RadioTile(
title: _radioButtons[index],
selected: _radioController.selectedIndex,
index: index,
onTap: () {
_radioController.selectIndex(index);
},
),
),
);
},
onSelected: (val, i, selected) =>
debugPrint('Button: $val index: $i $selected'),
),
),
),

                  Thanks in advance