Change background color of root view in SwiftUI, fixing white background during rotation

MyApp.swift

//
//  MyApp.swift
//  MyApp
//
//  Created by Brady Law on 8/25/23.
//

import SwiftUI

@main
struct MyApp: App {
    var body: some Scene {
        WindowGroup {
            ContentView()
                .background(.black)
                .onAppear {
                    if let window = (UIApplication.shared.connectedScenes.first as? UIWindowScene)?.windows.first {
                        window.rootViewController?.view.backgroundColor = .black
                    }
                }
        }
    }
}