Controlling View and NavigationBar of an App opened programmatically with open(_:options:completionHandler:)

Question

When I open a target iOS App programmatically from my App, the target App opens fine and works as expected. The target app opens as a Modal.automatic view. Here is the problem: the remaining visible sliver of the original App & Nav Bar is very dark, and the Nav button at the TopLeft of the screen window is Black and extremely hard to see. I know it is there but my users will be lost and unable to return to my App.

I can not find an approach to either move the target's modal window down a few pixels or otherwise make the Nav bar and its button (return to calling App) more prominent. I have tried altering the NavBar Appearance (Opaque, back = white, text=black), but my chosen colors persist on up to the first time the target is opened, after that the Nav Bar is dark translucent again.

Of note, the calling App's UIView has a view.background color which is a bright yellow pattern image. The call to the target App is routine:

    let appURLScheme = "xyzzy://"
    guard let appURL = URL(string: appURLScheme) else { return }
    if UIApplication.shared.canOpenURL(appURL) {
        UIApplication.shared.open(appURL,
                                  options: [:],
                                  completionHandler: nil )
    }