'*' if HEAD matches current ref (the checked out branch), ' '
otherwise.
+color::
+ Change output color. Followed by `:<colorname>`, where names
+ are described in `color.branch.*`.
+
In addition to the above, for commit and tag objects, the header
field names (`tree`, `parent`, `object`, `type`, and `tag`) can
be used to specify the value in the header field.