Changing all text color in Frame

Question

I want to change all my text in my application (wpf) programmatically, it works form my Grid on my mainwindow (BaseGrid) with:

private void setTextColor()
    {

       Color myColor = Brushes.Red;

            for (int i = 0; i < VisualTreeHelper.GetChildrenCount(BaseGrid); i++)
            {
                Visual childVisual = (Visual)VisualTreeHelper.GetChild(BaseGrid, i);

                    childVisual.Dispatcher.BeginInvoke(new Action(() =>
                        {
                            childVisual.SetValue(Label.ForegroundProperty, myColor);
                        }));                
            }
    }

but when i change the "BaseGrid" for "myFrame", text in myFrame is not being changed, I load pages in them. I want to be able to change the color in the Page in myFrame the same way.

Need some help here.