I know in general themes cannot be applied to Master pages. But I was wondering there can be some trick or way to do so. In my situation I dont want to apply these to the whole site but only on an application. Because in application there are many pages I cant do it manually. In my situation I am also not able to inherit page class. Any suggestion please. This project is in Asp.net 3.5
Thanks
Apparently, the only way to do this programmatically if you can’t inherit from a base class, is with an HTTP Module.
Check the following blog for an explanation: Set the Theme for a MasterPage (from code)
In your case you should first check the page’s master page before you set the page’s theme.