To apply a custom theme assembly to your project, do the following.
1. Add a reference to the assembly.
2. Assign the assembly name to the customThemeAssemblies option in the DevExpress web.config section.
3. Set a theme for a website via the DevExpress web.config section.
Note that you can specify a theme of a website using our DevExpress ASP.NET Project Wizard. In this case, all points above will be done automatically.