A bash pretty print script that provides following red/green/blue colored echo functions.

rgb-colored-echo.sh

#!/bin/bash
#
## @file                rgb-colored-echo.sh
## @author              Amber Jain
## @section DESCRIPTION	A bash pretty print script which provides red/green/blue colored echo functions
## @section LICENSE     ISC


#################
# Documentation #
#################
#
# A bash pretty print script which provides following red/green/blue colored echo functions:
#     red_echo
#     simple_red_echo
#     green_echo
#     simple_green_echo
#     blue_echo
#     simple_blue_echo
#
# Simple copy/paste function definitions or 'source' this script in your bash script and then you can use these functions.


##########################
# Start of script 'body' #
##########################

SELF_NAME=$(basename $0)

# Prints warning/error $MESSAGE in red foreground color
#
# For e.g. You can use the convention of using RED color for [E]rror messages
red_echo() {
    echo -e "\x1b[1;31m[E] $SELF_NAME: $MESSAGE\e[0m"
}

simple_red_echo() {
    echo -e "\x1b[1;31m$MESSAGE\e[0m"
}

# Prints success/info $MESSAGE in green foreground color
#
# For e.g. You can use the convention of using GREEN color for [S]uccess messages
green_echo() {
    echo -e "\x1b[1;32m[S] $SELF_NAME: $MESSAGE\e[0m"
}

simple_green_echo() {
    echo -e "\x1b[1;32m$MESSAGE\e[0m"
}

# Prints $MESSAGE in blue foreground color
#
# For e.g. You can use the convetion of using BLUE color for [I]nfo messages
# that require special user attention (especially when script requires input from user to continue)
blue_echo() {
    echo -e "\x1b[1;34m[I] $SELF_NAME: $MESSAGE\e[0m"
}

simple_blue_echo() {
    echo -e "\x1b[1;34m$MESSAGE\e[0m"
}

#########
# Usage #
#########
echo "This is a 'normal' echo!"
echo

MESSAGE="This is a RED colored message!" ; red_echo
MESSAGE="This is a simple RED colored message!" ; simple_red_echo
echo

MESSAGE="This is a GREEN colored message!" ; green_echo
MESSAGE="This is a simple GREEN colored message!" ; simple_green_echo
echo

MESSAGE="This is a BLUE colored message!" ; blue_echo
MESSAGE="This is a simple BLUE colored message!" ; simple_blue_echo

#################
# End of script #
#################

Doesn't work for me, with or without the -e I get

➜ ./scripts/setup.sh
This is a 'normal' echo!

-e \x1b[1;31m[E] setup.sh: This is a RED colored message!\e[0m
-e \x1b[1;31mThis is a simple RED colored message!\e[0m

-e \x1b[1;32m[S] setup.sh: This is a GREEN colored message!\e[0m
-e \x1b[1;32mThis is a simple GREEN colored message!\e[0m

-e \x1b[1;34m[I] setup.sh: This is a BLUE colored message!\e[0m
-e \x1b[1;34mThis is a simple BLUE colored message!\e[0m
➜  ./scripts/setup.sh
This is a 'normal' echo!

\x1b[1;31m[E] setup.sh: This is a RED colored message!\e[0m
\x1b[1;31mThis is a simple RED colored message!\e[0m

\x1b[1;32m[S] setup.sh: This is a GREEN colored message!\e[0m
\x1b[1;32mThis is a simple GREEN colored message!\e[0m

\x1b[1;34m[I] setup.sh: This is a BLUE colored message!\e[0m
\x1b[1;34mThis is a simple BLUE colored message!\e[0m

Try something like this

red_echo() {
    echo -e "\x1b[1;31m $1\e[0m"
}

green_echo() {
    echo -e "\x1b[1;32m $1\e[0m"
}

green_echo "Some description"

Try something like this

red_echo() {
    echo -e "\x1b[1;31m $1\e[0m"
}

green_echo() {
    echo -e "\x1b[1;32m $1\e[0m"
}

green_echo "Some description"

Seems like author does not use ascii colours, and this is the reason why your terminal emulator shows plain codes instead of colors.