`xx`; for example `%00` interpolates to `\0` (NUL),
`%09` to `\t` (TAB) and `%0a` to `\n` (LF).
---color[=<when>]:
+--color[=<when>]::
Respect any colors specified in the `--format` option. The
`<when>` field must be one of `always`, `never`, or `auto` (if
`<when>` is absent, behave as if `always` was given).