How to indent the output of a shell colorising stderr red

indented.sh

#!/usr/bin/env bash
#
# Based on http://stackoverflow.com/questions/9112979/pipe-stdout-and-stderr-to-two-different-processes-in-shell-script
set -e

function indented() {
    echo RUnNINg: $@
    (set -o pipefail; { "$@" 2>&3 | sed >&2 's/^/   | /'; } 3>&1 1>&2 | perl -pe 's/^(.*)$/\e[31m   | $1\e[0m/')
}

function die() { echo ERROR: $@ > /dev/stderr; exit 1; }


echo Welcome to the indented running example.

echo
echo Here is a curl run:
indented curl -v http://example.com

echo
echo Here\'s a pipeline
indented bash -c 'echo -n abc | wc -c'

An alternative would be to use the nl command:

ls -l | nl -bn -s '--| '
      --| total 320
      --| -rw-r--r--    1 tushar  staff    1045 17 Sep 15:58 LICENSE
      --| -rw-r--r--    1 tushar  staff    2297 17 Sep 15:58 README.md
...

Or even just sed!

ls -l | sed 's/^/   --| /'
   --| total 784
   --| -rw-r--r--     1 tpokle  SEEK\Domain Users    2377 21 Sep 17:04 Makefile
   --| -rw-r--r--     1 tpokle  SEEK\Domain Users     349 20 Sep 14:55 Makefile.development.cf
   --| -rw-r--r--     1 tpokle  SEEK\Domain Users     681 20 Sep 14:55 Makefile.production.cf
   --| -rw-r--r--     1 tpokle  SEEK\Domain Users    9181 20 Sep 14:55 README.md