Alerts and Action Sheets not using SwiftUI accent color

I was having the same problem for last half year, as I thought Apple will fix it before my app publication. However, it didn't happen and I had to find some way to make it working. Appears it's ease to fix with one line of code in SceneDelegate. The solution isn't perfect, as it overwrites all UIAlertController tintColor, but it works.

// SceneDelegate.swift

func scene(_ scene: UIScene, willConnectTo session: UISceneSession, options connectionOptions: UIScene.ConnectionOptions) {
  // ...
  UIView.appearance(whenContainedInInstancesOf: [UIAlertController.self]).tintColor = UIColor(named: "AccentColor")
  // ...
}

Based on maxtomczyk's fix the following seems to works fine with "new" App (no SceneDelegate.swift) (with universal AccentColor in assets ofc)

// root app file

@main
struct MyApp: App {

  init(){
    // override apple's buggy alerts tintColor
    UIView.appearance(whenContainedInInstancesOf: [UIAlertController.self]).tintColor = UIColor(named: "AccentColor")
  }

  var body: some Scene {
    WindowGroup {
      // content view...
    }
  }

}

It looks like the issue is with UIColor.tintColor.

A color value that resolves at runtime based on the current tint color of the app or trait hierarchy.

When adding this line of code:

UIView.appearance(whenContainedInInstancesOf: [UIAlertController.self]).tintColor = .tintColor

the same buggy behaviour occurs, but setting it to any other colour makes it work fine.

Apple's implementation must use UIColor.tintColor which is why alert buttons' colours are "broken".

All the solutions from this thread did not work for me when the application was in production. It only works during the development process. More over, I am not sure that adding the UIView.appearance(whenContainedInInstancesOf:) call within the @main app entry initializer is a good practice as swiftUI views call it every time the view redraws.

The trick for me was calling appearance without the parameter whenContainedInInstancesOf of appearance(), on a onAppear() modifier. It also work only when setting the color this way: UIColor(named: "AccentColor"). Calling UIColor(.accentColor)from SwiftUIColor` does not work.

@main
struct AwesomeApp: App {

  var body: some Scene {
    WindowGroup {
      Group {
        ContentView()
      }
      .onAppear { UIView.appearance().tintColor = UIColor(named: "AccentColor") }
    }
  }
}