For a concrete example, Alexei Chmelev’s Java Curses Library (JCurses) offers a JNI-based implementation that uses curses on Unix and Win32 to provide a platform-independent text windowing toolkit.

So, i've used setBackground (Color.white) on each of the Panels, and this works. But, there are still areas around these panels that are unaffected and remain the hideous java-gray.