color256test

#!/bin/sh
colorblock() { printf "\033[48;5;%sm %3d \033[0m" "$1" "$1"; }

for i in $(seq 0 15) ; do
    colorblock "$i"
    [ $(( i % 8 )) = 7 ] && printf "\n"
done

for i in $(seq 16 6 123) ; do
    for j in $(seq "$i" "$((i + 5))") ; do
        colorblock "$j"
    done
    for j in $(seq "$i" "$((i + 5))") ; do
        colorblock "$((j + 108))"
    done
    printf "\n"
done

for i in $(seq 232 255) ; do
    colorblock "$i"
    [ $(( i % 12 )) = 3 ] && printf "\n"
done