The RadMenuItem in RadContextMenu contains four control templates - TopLevelHeaderTemplate, TopLevelItemTemplate, SubMenuHeaderTemplate and SubMenuItemTemplate. Inside each of these control template there is a ButtonChrome control that is responsible for the visual states of the menu item. To cancel the mouse over effect, simply set RenderMouseOver = "False" to each of the ButtonChrome controls.
I hope this helps.
the Telerik team
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