Note that a link to the style sheet from the Monochrome theme folder is injected in the of
the page. The ASP.NET run time does this for every CSS file it finds in the currently active theme
folder (in alphabetical order), so be sure to keep your theme folder clean to avoid unnecessary
files from being included and downloaded by the browser. Also note that the is added just
right before the closing tag. This ensures that the theme file is included after all other
files you may have added yourself (through the master page, for example). This is in contrast to
how the styleSheetTheme attribute works. Because this type of theme allows its settings to be
overridden, it’s imported at the top of the file, giving room for other CSS files that follow it to
change the look and feel of the page.
7. Return to Visual Studio and open the master page file in Design View. Notice how all the design is
gone and VS now shows the basic layout of the page again. Unfortunately, VS does not display the
theme you’ve set using the theme attribute. However, you can overcome this limitation by setting
the styleSheetTheme instead. To do this, open the Web.config file again, locate the element
you created earlier, and add the following attribute: