disabled_text_button.dart

import 'package:flutter/material.dart';

class Home extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Center(
        child: TextButton.icon(
          icon: const Icon(Icons.check_box),
          label: const Text('TextButton'),
          style: ButtonStyle(
            foregroundColor: MaterialStateProperty.resolveWith<Color>(
              (Set<MaterialState> states) => states.contains(MaterialState.disabled) ? Colors.black : null,
            ),
          ),
          onPressed: null,
        ),
      ),
    );
  }
}

void main() {
  final ThemeData theme = ThemeData.light();
  runApp(MaterialApp(theme: theme, home: Home()));
}