You can use Style Explorer to find out which style you must config in a specific situation. In this case, just change the rollOverColor style to 0xFFFFFF (equals to the background color).
<mx:LinkButton label="Button 2" rollOverColor="0xFFFFFF" />
thats not what i mean. like if use the code to this application there is gray around the edges. i would like that gone so its just a button and vbox that opens
Is it the gap between the button and the VBox ?. If so, set the verticalGap style of the Application to 0.