The ScrollPane spec does not specify if invoking setBackground() on
a scrollpane sets the background color of the scrollpane's scrollbars
(in addition to the background color of the scrollpane's pane).
On Solaris, this method sets the background color of the scrollpane's
pane as well as that of its scrollbars, while on Windows, it sets
the background color of the scrollpane's pane only.