When drawing to drawing surfaces, ClearWin+ operates in one of two colour
modes; RGB mode or VGA mode. In VGA mode, colour
values are represented as indexes into a colour palette by which ClearWin+
emulates a DOS environment. This mode is useful for porting DOS programs to
Windows. Currently the default colour mode is VGA mode. In RGB
mode ClearWin+ uses RGB colours (the native Windows colour
representation). RGB mode is recommended for new programs.