How to get all elements from wrappanel?

Question

WPF

How to access each WrapPanel element and change the Background?
Code example:

public void AddTabMenu()
{
  var lb = new Label();
  var index = wpTopMenu.Children.Count;
  lb.Name = "Scene" + index;
  lb.Content = "Сцена " + index;
  lb.Style = this.Resources["tabMenu"] as Style;
  wpTopMenu.Children.Insert(index - 1, lb);
}

private void TextBlock_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)
{
  AddTabMenu();
}

private void Label_PreviewMouseLeftButtonDown(object sender, MouseButtonEventArgs e)
{
  if(sender is Label lb)
  {
    var index = wpTopMenu.Children.Count;
    for (int i = 0; i < index; i++)
    {
      var item = wpTopMenu.Children[i];
    }
    lb.Background = new SolidColorBrush(Color.FromArgb(255, 136, 0, 255));

    br.Children.RemoveAt(0);
  }
}

Answer 1

Assign a Background resource or a style to an element that refers to the Background,
then just change the color of the resource when necessary
Example code:
App.xaml

<Color x:Key="DecorateColor">#FF005087</Color>
<SolidColorBrush x:Key="BackgroundBrush" Color="{DynamicResource DecorateColor}"/>

elements where we change the color, for example, inside the style
change resource color

Color decorateColor = Color.Color.FromArgb(255, 136, 0, 255);
Application.Current.Resources["DecorateColor"] = decorateColor;

If you use MVVM, then you can solve it through StaticResource.
But this is a head-on approach, it will be more true through the style state, but it's up to you to first study Trigger (for this particular case, DataTrigger) and MVVM.