how to add color to border javafx code example

Example 1: add border color to acouintainer in flutter

Container(
  height: 100,
  width: 100,
  decoration: BoxDecoration(
    border: Border.all(
      color: Colors.blue,
    ),
    borderRadius: BorderRadius.circular(10.0),
  ),
  child: Center(
    child: Text('mrflutter.com'),
  ),
),

Example 2: add border to button swiftui

Button(action: {
        print("sign up bin tapped")
    }) {
        Text("SIGN UP")
            .frame(minWidth: 0, maxWidth: .infinity)
            .font(.system(size: 18))
            .padding()
            .foregroundColor(.white)
            .overlay(
                RoundedRectangle(cornerRadius: 25)
                    .stroke(Color.white, lineWidth: 2)
        )
    }