I can't change the color of the ElevatedButton. Flutter

Question

What is the problem?
The button is located on the background of the gradient and takes its color and i can't change the color..
Maybe the problem is in the gradient? Although I tried to remove the decoration of the container, it did not help. Maybe it's a container?

@override
  Widget build(BuildContext context) {
    return Scaffold(
      resizeToAvoidBottomInset: false,
      body: Container(
        decoration: BoxDecoration(
          gradient: LinearGradient(
              begin: Alignment.topLeft,
              end: Alignment.bottomRight,
              colors: [Colors.black, Colors.blue]),
        ),
        child: Column(
          mainAxisAlignment: MainAxisAlignment.spaceAround,
          crossAxisAlignment: CrossAxisAlignment.center,
          children: <Widget>[
            Padding(...),
            CircularPercentIndicator(...),
            Padding(...),
            SizedBox(height: 20),
            Padding(
              padding: EdgeInsets.only(bottom: 30.0),
              child: ElevatedButton(
                child: Text("Start destroying"),
                onPressed: null,
                style: ElevatedButton.styleFrom(
                  shape: RoundedRectangleBorder(
                    borderRadius: BorderRadius.circular(30.0),
                  ),
                  primary: Colors.black,
                  padding: EdgeInsets.symmetric(horizontal: 60, vertical: 15),
                  textStyle: TextStyle(
                    fontSize: 25,
                    color: Colors.white,
                  ),
                ),
              ),
            ),
          ],
        ),
      ),
    );
  }

Answer 1

You need to set a non-null onPressed function for the ElevatedButton :

ElevatedButton(
  child: Text("Start destroying"),
  onPressed: () {}, // add this
  style: ElevatedButton.styleFrom(
    shape: RoundedRectangleBorder(
      borderRadius: BorderRadius.circular(30.0),
    ),
    primary: Colors.red,
    padding: EdgeInsets.symmetric(horizontal: 60, vertical: 15),
    textStyle: TextStyle(
      fontSize: 25,
      color: Colors.white,
    ),
  ),
),