Hello Zamel,
I would suggest you to use ImplictStyles in your application. You can check our
online help for more information about implicit styles. There you will find an example how to set style for a specific control and use your theme as well. Also you can check
this article where you will find explanation of all templates used in
RadMenu.
Hopefully this helps.
Regards,
Rosen Vladimirov
the Telerik team