This "color" simply reverts background and foreground. It will be used
in the upcoming "dual color" mode of `git range-diff`, where we will
reverse colors for the -/+ markers and the fragment headers of the
"outer" diff.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>