You can check our online help for applying different styles in your application. If you check your installation folder for RadControls you`ll find there "Themes.Implicit" directory in which we are storing all themes and templates that are using for our controls. If you want to modify only the behaviour of RadMenu and RadMenuItem you can check this blog post and use the tool from it to extract only the menu xaml styles. Please note that RadMenu and RadMenuItem templates are included in Telerik.Windows.Controls.Naviagation and this is the XAML file that you have to load in the TelerikStlyesExplorer described in the post.
To be more clear we have created a sample project for you where we have extracted menu XAML and we have applied several changes in it so now the yellowish effect is switched off. Of course if you want a different behaviour you can apply other modifications in the XAML file.
Please notice that you`ll have to merge the resource dictionaries in the App.xaml file:
We also noticed you have another forum post here - we are using the same project in it to try to resolve your problem - in "MenuImplicitStyles.xaml" you can find some changed lines for popup but I`ll explain them in the other forum post.
Please check the attached project and inform us should you have any other concerns.
Thanks for quick guidelines how i can modify implicit styles. During r & d, i found, radmenu uses [buttonchrome] in-built for radmenuitems. so i've created separate static styles for [buttonchrome] control & by doing that, i resolved my problem.
I am going to check what you suggested & will surely adapt it in future.