Display settings
Contrary to popular assumptions, what you see is not always what you get. Microsoft Expression Design offers several ways to customize what you see on screen, and while each affects your view, none affects your final output (whether that be XAML or Print, Exported Image file). For example, you can turn off the rendering of stroke and fill effects so that you see only the paths themselves. This might be helpful when trying to figure out how someone else built a complex image.
You can find most of the display settings on the View menu, and the rest in the Options dialog box.