Default templates for Windows Phone application comes with few basic set of resource elements that defines the controls color, size, background etc. To examine it more closely; you may noticed the MainPage.Xaml created with the default template has three page level styles defined as static resources.
In a quick thoughts, you may try to explore your solution to find out where are those styles defined. But, you can not find these resources in your solution. These resources are the global Windows Phone resources and can be accessible to any of the Windows Phone Application.
The easiest way to locate and look around the definition of the resources is to select the “Go To Definition (F12)” against each resources.
Must Read :Go To Definition in XAML Code Editor – Visual Studio 2013
So for any control, if you need to apply the predefined styles, you have to apply the style by mentioning the resource name. With the help of Visual Studio, you can use this feature very easily by just apply the styles in the designer .
Step 1. Select the element and right click to display the context menu .
Step 2. Select “Edit Style” -> “Apply Resource” and then select the predefined styles from the list of resources as shown in the below image.
You will find the style is applied and an element has been added with the control
