Flutter:如何给ToggleButtons的每个按钮上色

import 'package:flutter/material.dart';

void main() {
  runApp(MaterialApp(
    home: MyToggleButtons(),
  ));
}

class MyToggleButtons extends StatefulWidget {
  @override
  _MyToggleButtonsState createState() => _MyToggleButtonsState();
}

class _MyToggleButtonsState extends State<MyToggleButtons> {
  List<bool> isSelected = [false, false, false];

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Toggle Buttons'),
      ),
      body: Center(
        child: ToggleButtons(
          isSelected: isSelected,
          color: Colors.white,
          selectedColor: Colors.red,
          fillColor: Colors.blue,
          children: <Widget>[
            Icon(Icons.favorite),
            Icon(Icons.star),
            Icon(Icons.camera),
          ],
          onPressed: (int index) {
            setState(() {
              isSelected[index] = !isSelected[index];
            });
          },
        ),
      ),
    );
  }
}