Print all possible combinations of bash colors, according to Advanced Bash-Scripting Guide
#! /bin/bash
for isBold in {0..1}; do
for background in {40..47}; do
for foreground in {30..37}; do
colorTag='\e['$isBold';'$foreground';'$background'm'
colorResetTag='\e[0m'
text=$colorTag'isBold:'$isBold' foreground:'$foreground' background:'$background$colorResetTag
echo -e $text
done
echo '================'
done
done