option and lists the commits in that commit range like the 'summary'
option of linkgit:git-submodule[1] does.
---color::
+--color[=<when>]::
Show colored diff.
+ The value must be always (the default), never, or auto.
--no-color::
Turn off colored diff, even when the configuration file
gives the default to color output.
+ Same as `--color=never`.
--color-words[=<regex>]::
Show colored word diff, i.e., color words which have changed.