[GNC] Modify Buttons on Select

[Larry Baldwin]

Trying to determine if it is possible to modify the   'Help'  /    'Close/Cancel'   /    'OK'   Buttons on the various Windows.

Currently, when I tab on to the buttons the border changes from single to double border (grey on light grey) providing minimal visible change making it difficult to see if the button is selected. 

Is a global CSS class available to modify the button border, text, or background color when the button is selected?

(Mac environment)

thanks for any tips....

Larry