Thank you for contacting us.
Could you please share with us what exactly you are trying to achieve. Also, the style of the RadMenuItem contains ButtonChrome control, which represents the states of the MenuItem. If that is what you want to change, then you have to edit the ButtonChrome style. For more information you could refer to this KB article
. Even though it is for WPF, it will give you general idea of the case. One for SL is coming soon.
Hope this information helps. If you have further questions please let us know.
the Telerik team
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