How do i change the look of a tabitem? Literally Nothing happens no matter what i add to it

Question

So i Have this NavBar with five items. The middle one is suppose to be a little bit bigger, have a orange background and have the logo of openai (its a school project). But no matter what i add to the tabitem, literally nothing happens.....

struct ContentView: View {
    @State var workoutPlansManager = WorkoutPlansManager()
    @State var exerciseManager = ExercisesManager()

    init(){
        UINavigationBar.appearance().largeTitleTextAttributes = [.foregroundColor : UIColor.init(Color.white)
        ]
    }
    var body: some View {
        NavigationStack {
            TabView {
                HomeScreen(workoutPlansManager: workoutPlansManager, exerciseManager: exerciseManager)
                    .tabItem {
                        Label("Home", systemImage: "house")
                    }
                
                WorkoutPlansScreen(workoutPlansManager: workoutPlansManager, exerciseManager: exerciseManager)
                    .tabItem {
                        Label("Home", systemImage: "house")
                    }
                
                AiScreen()
                    .tabItem {
                        Image("openai").font(.largeTitle)
                    }
                
                ExercisesScreen(exercisesManager: exerciseManager)
                    .tabItem {
                        Label("Home", systemImage: "house")
                    }

                
                TimerScreen()
                    .tabItem {
                        Label("Home", systemImage: "house")
                    }
            }
            .onAppear{
                UITabBar.appearance().barTintColor = UIColor(.black)
                UITabBar.appearance().backgroundColor = UIColor(.black)
                UITabBar.appearance().unselectedItemTintColor = UIColor(.white)

            }
        }
        .foregroundColor(Color.white)

    }
}

I have tried to add frame, font and everything, but nothing happens to anything inside of a tabitem as well as the tabitem itself.. what am i doing wrong? :/