Prints each color in the palette on terminal emulator.

colors.sh

#!/usr/bin/env bash

for i in {0..255}; do
  printf "\x1b[48;5;%sm%3d\e[0m " "$i" "$i"
  if (( i == 15 )) || (( i > 15 )) && (( (i-15) % 6 == 0 )); then
    printf "\n"
  fi
done