Thank you for writing and for the attached screen shot.
You can hide the button fill and border by using the following two lines of code:
.radRibbonBar1.RibbonBarElement.ApplicationButtonElement.ActionButton.ButtonFillElement.Visibility = ElementVisibility.Hidden;
.radRibbonBar1.RibbonBarElement.ApplicationButtonElement.ActionButton.BorderElement.Visibility = ElementVisibility.Hidden;
I hope this will help you. If you have other questions, feel free to write back.
the Telerik team
Q2’11 SP1 of RadControls for WinForms is available for download (see what's new); also available is the Q3'11 Roadmap for Telerik Windows Forms controls.