basic colors accepted are `normal`, `black`, `red`, `green`,
`yellow`, `blue`, `magenta`, `cyan`, `white` and `default`.  The first
color given is the foreground; the second is the background.  All the
basic colors except `normal` and `default` have a bright variant that can
be specified by prefixing the color with `bright`, like `brightred`.
+
The color `normal` makes no change to the color. It is the same as an
empty string, but can be used as the foreground color when specifying a
background color alone (for example, "normal red").
+
The color `default` explicitly resets the color to the terminal default,
for example to specify a cleared background. Although it varies between
terminals, this is usually not the same as setting to "white black".
+
Colors may also be given as numbers between 0 and 255; these use ANSI
256-color mode (but note that not all terminals may support this).  If
your terminal supports it, you may also specify 24-bit RGB values as
hex, like `#ff0ab3`, or 12-bit RGB values like `#f1b`, which is
equivalent to the 24-bit color `#ff11bb`.
+
The accepted attributes are `bold`, `dim`, `ul`, `blink`, `reverse`,
`italic`, and `strike` (for crossed-out or "strikethrough" letters).
The position of any attributes with respect to the colors
(before, after, or in between), doesn't matter. Specific attributes may
be turned off by prefixing them with `no` or `no-` (e.g., `noreverse`,
`no-ul`, etc).
+
The pseudo-attribute `reset` resets all colors and attributes before
applying the specified coloring. For example, `reset green` will result
in a green foreground and default background without any active
attributes.
+
An empty color string produces no color effect at all. This can be used
to avoid coloring specific elements without disabling color entirely.
+
For git's pre-defined color slots, the attributes are meant to be reset
at the beginning of each item in the colored output. So setting
`color.decorate.branch` to `black` will paint that branch name in a
plain `black`, even if the previous thing on the same output line (e.g.
opening parenthesis before the list of branch names in `log --decorate`
output) is set to be painted with `bold` or some other attribute.
However, custom log formats may do more complicated and layered
coloring, and the negated forms may be useful there.

pathname::
	A variable that takes a pathname value can be given a
	string that begins with "`~/`" or "`~user/`", and the usual
	tilde expansion happens to such a string: `~/`
	is expanded to the value of `$HOME`, and `~user/` to the
	specified user's home directory.
+
If a path starts with `%(prefix)/`, the remainder is interpreted as a
path relative to Git's "runtime prefix", i.e. relative to the location
where Git itself was installed. For example, `%(prefix)/bin/` refers to
the directory in which the Git executable itself lives. If Git was
compiled without runtime prefix support, the compiled-in prefix will be
substituted instead. In the unlikely event that a literal path needs to
be specified that should _not_ be expanded, it needs to be prefixed by
`./`, like so: `./%(prefix)/bin`.


Variables
~~~~~~~~~

Note that this list is non-comprehensive and not necessarily complete.
For command-specific variables, you