I used RadPageView under the theme "VisualStudio2012LightTheme" .
The ViewMode of RadPageview is Stack.
I wanted to change the font size of page header in runtime but it was not workable.
If I changed the theme to VisualStudio2012DarkTheme or Office2013LightTheme, it worked fine.
foreach
(RadPageViewPage page
in
PageViewFunc.Pages)
{
page.Item.Font = font;
}