Is it possible to hide the markup grid's focus indicator?

Hey guys,

I've recently started developing my first roku application.

I have a markup grid with some images to select and two buttons above the grid. With the onKeyEvent  method, I am listening for user input and focus the buttons above. Everything works fine, but the focus indicator stays at the last selected element in the first row. I want to hide the focus indicator if one of the buttons is focused. 

Is this possible?

Thank you!