ranbow animation in bash

ranbow.sh

#!/bin/bash

RAINBOW=(196 202 208 214 220 226 190 154 118 82 46 46 47 48 49 50 51 45 39 33 27 21 21 57 93 129 165 201 200 199 198 197 196)

function char_rainbow() {
	local STR="$1" I
	J=$(( $J % ${#RAINBOW[@]} ))
	for I in $(seq 0 $(( ${#STR} - 1 )) ) ; do
		printf "\e[38;5;%dm%c" "${RAINBOW[J]}" "${STR:${I}:1}"
		J=$(( $J + 1 ))
		if [[ $J -eq ${#RAINBOW[@]} ]]; then
			J=0
		fi
	done
	printf "\e[0m\e[K\n"
}

function frame() {
	local J JJ=$1 NN=$2
	J=$(( $JJ + $NN * 1 ))
	char_rainbow ' _    _ ______ _      _      ____   __          ______  _____  _      _____  '
	J=$(( $JJ + $NN * 2 ))
	char_rainbow '| |  | |  ____| |    | |    / __ \  \ \        / / __ \|  __ \| |    |  __ \ '
	J=$(( $JJ + $NN * 3 ))
	char_rainbow '| |__| | |__  | |    | |   | |  | |  \ \  /\  / / |  | | |__) | |    | |  | |'
	J=$(( $JJ + $NN * 4 ))
	char_rainbow '|  __  |  __| | |    | |   | |  | |   \ \/  \/ /| |  | |  _  /| |    | |  | |'
	J=$(( $JJ + $NN * 5 ))
	char_rainbow '| |  | | |____| |____| |___| |__| |    \  /\  / | |__| | | \ \| |____| |__| |'
	J=$(( $JJ + $NN * 6 ))
	char_rainbow '|_|  |_|______|______|______\____/      \/  \/   \____/|_|  \_\______|_____/ '
}

for L in $(seq 0 10); do
	for I in $(seq 0 3 $(( ${#RAINBOW[@]} - 1 )) ) ; do
		echo -ne "\e[s"
		echo -ne "\e[1000A\r"
		frame $I 2
		echo -ne "\e[u"
		sleep 0.1
	done
done