title: Flutter ,dart,The parameter 'colour' can't have a value of 'null' because of its type, but the implicit default value is 'null'
body: <p>i dont know why i am getting the errors,i have previously coded the same and it worked perfectly fine maybe some new update or plugin please help me solve my error</p>
  <pre><code>import 'package:flutter/material.dart';
  
  class RoundedButton extends StatelessWidget {
    final String title;
    final Color colour;
    final Function onPressed;
    RoundedButton({this.title, this.colour, @required this.onPressed});
  
    @override
    Widget build(BuildContext context) {
      return Padding(
        padding: EdgeInsets.symmetric(vertical: 16.0),
        child: Material(
          elevation: 5.0,
          color: colour,
          borderRadius: BorderRadius.circular(30.0),
          child: MaterialButton(
            onPressed: onPressed,
            minWidth: 200.0,
            height: 42.0,
            child: Text(
              title,
              style: TextStyle(color: Colors.white),
            ),
          ),
        ),
      );
    }
  }
  </code></pre>
  <p><a href="https://i.stack.imgur.com/9k54P.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/9k54P.png" alt="enter image description here" /></a></p>