#!/bin/bash
for color in {0..255}; do
printf "\x1b[38;5;${color}m %3s \e[0m" $color #fg
printf "\x1b[48;5;${color}m %3s \e[0m" $color #bg
if [ $((($color + 1) % 8)) == 0 ] ; then
echo #New line
fi
done