Вывести в терминале последние 20строк файла одним цветом ,остальное другим?

$ cat n20.sh
#!/usr/bin/bash

echo -e '\e[0;31m'
head -n-20 "$1"
echo -e '\e[1;33m'
tail -n20 "$1"
echo -e '\e[0m'

$ chmod +x n20.sh
$ ./n20.sh /tmp/test
...

tput setaf 1; head -n -20 /var/log/auth.log && tput setaf 2; tail -n -20 /var/log/auth.log

fortune | cowsay > /tmp/cowsay ;
grep -e '--------$' /tmp/cowsay -B50 -A0 | lolcat -F 0.0033 ;
tail -n 20 /tmp/cowsay | lolcat -a -s 500 -F 3 ;echo " " ; sleep 4s ; clear ;

fortune | cowsay  >  /tmp/cowsay ;
NUMS=$(cat /tmp/cowsay | wc -l)
let HEAD=$NUMS-20
head -n $HEAD /tmp/cowsay | lolcat -F 0.0033  ;
tail -n 20  /tmp/cowsay | lolcat -a -s 500 -F 3 ;echo " ";sleep 4s ;clear ;

cat bar | perl -MTerm::ANSIColor -e'print color(++$i<20?red:yellow).$_.${POPCOLOR}while<>'

cat bar | perl -MTerm::ANSIColor -e'@F=<>;print color(@F>20?red:yellow),shift@F,${POPCOLOR}while@F'

cat  /tmp/test | perl -MTerm::ANSIColor -e'@F=<>;print color(@F-++$i>20?red:yellow),$_ for@F'

TMP=`mktemp`
fortune | cowsay  >  $TMP

#!/bin/bash

show_n() {
        local i v
        echo -n "$1"
        for ((i=$2;i<$3;i++)); do
                v=$4[$i]
                echo "${!v}"
        done
}

n=0
while IFS='
' read -r l; do
        lines[n++]=$l
done < <(fortune | cowsay)
first=$(($n-20))
show_n "$(tput setaf 1)" 0 $first lines
show_n "$(tput setaf 2)" $first $n lines
echo -n "$(tput setaf 0)"

#!/bin/ash

show_pseudo_array() {
        local i
        echo -n "$1"
        i=$2
        while [ $i -lt $3 ]; do
                i=$(($i+1))
                eval echo \"\$$4$i\"
        done
}

n=0
fortune | cowsay {
while IFS='
' read l; do
        n=$(($n+1))
        eval l$n=\$l
done
first=$(($n-20))
show_pseudo_array "$(tput setaf 1)" 0 $first l
show_pseudo_array "$(tput setaf 2)" $first $n l
echo -n "$(tput setaf 0)"
}