How to change the output color of echo in Linux

You can use these ANSI escape codes:

Black        0;30     Dark Gray     1;30
Red          0;31     Light Red     1;31
Green        0;32     Light Green   1;32
Brown/Orange 0;33     Yellow        1;33
Blue         0;34     Light Blue    1;34
Purple       0;35     Light Purple  1;35
Cyan         0;36     Light Cyan    1;36
Light Gray   0;37     White         1;37

And then use them like this in your script:

#    .---------- constant part!
#    vvvv vvvv-- the code from above
RED='\033[0;31m'
NC='\033[0m' # No Color
printf "I ${RED}love${NC} Stack Overflow\n"

which prints love in red.

From @james-lim's comment, if you are using the echo command, be sure to use the -e flag to allow backslash escapes.

# Continued from above example
echo -e "I ${RED}love${NC} Stack Overflow"

(don't add "\n" when using echo unless you want to add an additional empty line)

some variables that you can use:

# Reset
Color_Off='\033[0m'       # Text Reset

# Regular Colors
Black='\033[0;30m'        # Black
Red='\033[0;31m'          # Red
Green='\033[0;32m'        # Green
Yellow='\033[0;33m'       # Yellow
Blue='\033[0;34m'         # Blue
Purple='\033[0;35m'       # Purple
Cyan='\033[0;36m'         # Cyan
White='\033[0;37m'        # White

# Bold
BBlack='\033[1;30m'       # Black
BRed='\033[1;31m'         # Red
BGreen='\033[1;32m'       # Green
BYellow='\033[1;33m'      # Yellow
BBlue='\033[1;34m'        # Blue
BPurple='\033[1;35m'      # Purple
BCyan='\033[1;36m'        # Cyan
BWhite='\033[1;37m'       # White

# Underline
UBlack='\033[4;30m'       # Black
URed='\033[4;31m'         # Red
UGreen='\033[4;32m'       # Green
UYellow='\033[4;33m'      # Yellow
UBlue='\033[4;34m'        # Blue
UPurple='\033[4;35m'      # Purple
UCyan='\033[4;36m'        # Cyan
UWhite='\033[4;37m'       # White

# Background
On_Black='\033[40m'       # Black
On_Red='\033[41m'         # Red
On_Green='\033[42m'       # Green
On_Yellow='\033[43m'      # Yellow
On_Blue='\033[44m'        # Blue
On_Purple='\033[45m'      # Purple
On_Cyan='\033[46m'        # Cyan
On_White='\033[47m'       # White

# High Intensity
IBlack='\033[0;90m'       # Black
IRed='\033[0;91m'         # Red
IGreen='\033[0;92m'       # Green
IYellow='\033[0;93m'      # Yellow
IBlue='\033[0;94m'        # Blue
IPurple='\033[0;95m'      # Purple
ICyan='\033[0;96m'        # Cyan
IWhite='\033[0;97m'       # White

# Bold High Intensity
BIBlack='\033[1;90m'      # Black
BIRed='\033[1;91m'        # Red
BIGreen='\033[1;92m'      # Green
BIYellow='\033[1;93m'     # Yellow
BIBlue='\033[1;94m'       # Blue
BIPurple='\033[1;95m'     # Purple
BICyan='\033[1;96m'       # Cyan
BIWhite='\033[1;97m'      # White

# High Intensity backgrounds
On_IBlack='\033[0;100m'   # Black
On_IRed='\033[0;101m'     # Red
On_IGreen='\033[0;102m'   # Green
On_IYellow='\033[0;103m'  # Yellow
On_IBlue='\033[0;104m'    # Blue
On_IPurple='\033[0;105m'  # Purple
On_ICyan='\033[0;106m'    # Cyan
On_IWhite='\033[0;107m'   # White

the escape character in bash, hex and octal respectively:

|       | bash  | hex     | octal   | NOTE                         |
|-------+-------+---------+---------+------------------------------|
| start | \e    | \x1b    | \033    |                              |
| start | \E    | \x1B    | -       | x cannot be capital          |
| end   | \e[0m | \x1b[0m | \033[0m |                              |
| end   | \e[m  | \x1b[m  | \033[m  | 0 is appended if you omit it |
|       |       |         |         |                              |

short example:

| color       | bash         | hex            | octal          | NOTE                                  |
|-------------+--------------+----------------+----------------+---------------------------------------|
| start green | \e[32m<text> | \x1b[32m<text> | \033[32m<text> | m is NOT optional                     |
| reset       | <text>\e[0m  | <text>\1xb[0m  | <text>\033[om  | o is optional (do it as best practice |
|             |              |                |                |                                       |

bash exception:

If you are going to use these codes in your special bash variables

PS0

PS1

PS2 (= this is for prompting)

PS4

you should add extra escape characters so that bash can interpret them correctly. Without this adding extra escape characters it works but you will face problems when you use Ctrl + r for search in your history.

exception rule for bash

You should add \[ before any starting ANSI code and add \] after any ending ones.
Example:
in regular usage: \033[32mThis is in green\033[0m
for PS0/1/2/4: \[\033[32m\]This is in green\[\033[m\]

\[ is for start of a sequence of non-printable characters
\] is for end of a sequence of non-printable characters

Tip: for memorize it you can first add \[\] and then put your ANSI code between them:

\[start-ANSI-code\]

\[end-ANSI-code\]

type of color sequence:

3/4 bit 8 bit 24 bit

Before diving into these colors, you should know about 4 modes with these codes:

1. color-mode

It modifies the style of color NOT text. For example make the color bright or darker.

0 reset

1; lighter than normal

2; darker than normal

This mode is not supported widely. It is fully support on Gnome-Terminal.

2. text-mode

This mode is for modifying the style of text NOT color.

3; italic

4; underline

5; blinking (slow)

6; blinking (fast)

7; reverse

8; hide

9; cross-out

and are almost supported.
For example KDE-Konsole supports 5; but Gnome-Terminal does not and Gnome supports 8; but KDE does not.

3. foreground mode

This mode is for colorizing the foreground.

4. background mode

This mode is for colorizing the background.

The below table shows a summary of 3/4 bit version of ANSI-color

|------------+----------+---------+-------+------------------+------------------------------+--------------------------------------|
| color-mode | octal    | hex     | bash  | description      | example (= in octal)         | NOTE                                 |
|------------+----------+---------+-------+------------------+------------------------------+--------------------------------------|
|          0 | \033[0m  | \x1b[0m | \e[0m | reset any affect | echo -e "\033[0m"            | 0m equals to m                       |
|          1 | \033[1m  |         |       | light (= bright) | echo -e "\033[1m####\033[m"  | -                                    |
|          2 | \033[2m  |         |       | dark (= fade)    | echo -e "\033[2m####\033[m"  | -                                    |
|------------+----------+---------+-------+------------------+------------------------------+--------------------------------------|
|  text-mode | ~        |         |       | ~                | ~                            | ~                                    |
|------------+----------+---------+-------+------------------+------------------------------+--------------------------------------|
|          3 | \033[3m  |         |       | italic           | echo -e "\033[3m####\033[m"  |                                      |
|          4 | \033[4m  |         |       | underline        | echo -e "\033[4m####\033[m"  |                                      |
|          5 | \033[5m  |         |       | blink (slow)     | echo -e "\033[3m####\033[m"  |                                      |
|          6 | \033[6m  |         |       | blink (fast)     | ?                            | not wildly support                   |
|          7 | \003[7m  |         |       | reverse          | echo -e "\033[7m####\033[m"  | it affects the background/foreground |
|          8 | \033[8m  |         |       | hide             | echo -e "\033[8m####\033[m"  | it affects the background/foreground |
|          9 | \033[9m  |         |       | cross            | echo -e "\033[9m####\033[m"  |                                      |
|------------+----------+---------+-------+------------------+------------------------------+--------------------------------------|
| foreground | ~        |         |       | ~                | ~                            | ~                                    |
|------------+----------+---------+-------+------------------+------------------------------+--------------------------------------|
|         30 | \033[30m |         |       | black            | echo -e "\033[30m####\033[m" |                                      |
|         31 | \033[31m |         |       | red              | echo -e "\033[31m####\033[m" |                                      |
|         32 | \033[32m |         |       | green            | echo -e "\033[32m####\033[m" |                                      |
|         33 | \033[33m |         |       | yellow           | echo -e "\033[33m####\033[m" |                                      |
|         34 | \033[34m |         |       | blue             | echo -e "\033[34m####\033[m" |                                      |
|         35 | \033[35m |         |       | purple           | echo -e "\033[35m####\033[m" | real name: magenta = reddish-purple  |
|         36 | \033[36m |         |       | cyan             | echo -e "\033[36m####\033[m" |                                      |
|         37 | \033[37m |         |       | white            | echo -e "\033[37m####\033[m" |                                      |
|------------+----------+---------+-------+------------------+------------------------------+--------------------------------------|
|         38 | 8/24     |                    This is for special use of 8-bit or 24-bit                                            |
|------------+----------+---------+-------+------------------+------------------------------+--------------------------------------|
| background | ~        |         |       | ~                | ~                            | ~                                    |
|------------+----------+---------+-------+------------------+------------------------------+--------------------------------------|
|         40 | \033[40m |         |       | black            | echo -e "\033[40m####\033[m" |                                      |
|         41 | \033[41m |         |       | red              | echo -e "\033[41m####\033[m" |                                      |
|         42 | \033[42m |         |       | green            | echo -e "\033[42m####\033[m" |                                      |
|         43 | \033[43m |         |       | yellow           | echo -e "\033[43m####\033[m" |                                      |
|         44 | \033[44m |         |       | blue             | echo -e "\033[44m####\033[m" |                                      |
|         45 | \033[45m |         |       | purple           | echo -e "\033[45m####\033[m" | real name: magenta = reddish-purple  |
|         46 | \033[46m |         |       | cyan             | echo -e "\033[46m####\033[m" |                                      |
|         47 | \033[47m |         |       | white            | echo -e "\033[47m####\033[m" |                                      |
|------------+----------+---------+-------+------------------+------------------------------+--------------------------------------|
|         48 | 8/24     |                    This is for special use of 8-bit or 24-bit                                            |                                                                                       |
|------------+----------+---------+-------+------------------+------------------------------+--------------------------------------|

The below table shows a summary of 8 bit version of ANSI-color

|------------+-----------+-----------+---------+------------------+------------------------------------+-------------------------|
| foreground | octal     | hex       | bash    | description      | example                            | NOTE                    |
|------------+-----------+-----------+---------+------------------+------------------------------------+-------------------------|
|        0-7 | \033[38;5 | \x1b[38;5 | \e[38;5 | standard. normal | echo -e '\033[38;5;1m####\033[m'   |                         |
|       8-15 |           |           |         | standard. light  | echo -e '\033[38;5;9m####\033[m'   |                         |
|     16-231 |           |           |         | more resolution  | echo -e '\033[38;5;45m####\033[m'  | has no specific pattern |
|    232-255 |           |           |         |                  | echo -e '\033[38;5;242m####\033[m' | from black to white     |
|------------+-----------+-----------+---------+------------------+------------------------------------+-------------------------|
| foreground | octal     | hex       | bash    | description      | example                            | NOTE                    |
|------------+-----------+-----------+---------+------------------+------------------------------------+-------------------------|
|        0-7 |           |           |         | standard. normal | echo -e '\033[48;5;1m####\033[m'   |                         |
|       8-15 |           |           |         | standard. light  | echo -e '\033[48;5;9m####\033[m'   |                         |
|     16-231 |           |           |         | more resolution  | echo -e '\033[48;5;45m####\033[m'  |                         |
|    232-255 |           |           |         |                  | echo -e '\033[48;5;242m####\033[m' | from black to white     |
|------------+-----------+-----------+---------+------------------+------------------------------------+-------------------------|

The 8-bit fast test:
for code in {0..255}; do echo -e "\e[38;05;${code}m $code: Test"; done

The below table shows a summary of 24 bit version of ANSI-color

|------------+-----------+-----------+---------+-------------+------------------------------------------+-----------------|
| foreground | octal     | hex       | bash    | description | example                                  | NOTE            |
|------------+-----------+-----------+---------+-------------+------------------------------------------+-----------------|
|      0-255 | \033[38;2 | \x1b[38;2 | \e[38;2 | R = red     | echo -e '\033[38;2;255;0;02m####\033[m'  | R=255, G=0, B=0 |
|      0-255 | \033[38;2 | \x1b[38;2 | \e[38;2 | G = green   | echo -e '\033[38;2;;0;255;02m####\033[m' | R=0, G=255, B=0 |
|      0-255 | \033[38;2 | \x1b[38;2 | \e[38;2 | B = blue    | echo -e '\033[38;2;0;0;2552m####\033[m'  | R=0, G=0, B=255 |
|------------+-----------+-----------+---------+-------------+------------------------------------------+-----------------|
| background | octal     | hex       | bash    | description | example                                  | NOTE            |
|------------+-----------+-----------+---------+-------------+------------------------------------------+-----------------|
|      0-255 | \033[48;2 | \x1b[48;2 | \e[48;2 | R = red     | echo -e '\033[48;2;255;0;02m####\033[m'  | R=255, G=0, B=0 |
|      0-255 | \033[48;2 | \x1b[48;2 | \e[48;2 | G = green   | echo -e '\033[48;2;;0;255;02m####\033[m' | R=0, G=255, B=0 |
|      0-255 | \033[48;2 | \x1b[48;2 | \e[48;2 | B = blue    | echo -e '\033[48;2;0;0;2552m####\033[m'  | R=0, G=0, B=255 |
|------------+-----------+-----------+---------+-------------+------------------------------------------+-----------------|

some screen-shots

foreground 8-bit summary in a .gif

https://i.stack.imgur.com/EE4ta.gif

background 8-bit summary in a .gif

https://i.stack.imgur.com/N00Pj.gif

color summary with their values

https://i.stack.imgur.com/UplLQm.png

blinking on KDE-Terminal

https://i.stack.imgur.com/y38Aj.gif

https://i.stack.imgur.com/s887h.png

https://i.stack.imgur.com/Nsqn1.png

color-mode shot

https://i.stack.imgur.com/3tNRE.png

text mode shot

https://i.stack.imgur.com/dhcLE.png

combining is OK

https://i.stack.imgur.com/qGvoF.png

more shots

Tips and Tricks for Advanced Users and Programmers:

Can we use these codes in a programming language?

Yes, you can. I experienced in bash, c, c++, d perl, python

Do they slow down the speed of a program?

I think, NO.

Can we use these on Windows?

3/4-bit Yes, if you compile the code with gcc
some screen-shots on Win-7

How to calculate the length of code?

\033[ = 2, other parts 1

Where can we use these codes?

Anywhere that has a tty interpreter
xterm, gnome-terminal, kde-terminal, mysql-client-CLI and so on.
For example if you want to colorize your output with mysql you can use Perl

#!/usr/bin/perl -n
print "\033[1m\033[31m$1\033[36m$2\033[32m$3\033[33m$4\033[m" while /([|+-]+)|([0-9]+)|([a-zA-Z_]+)|([^\w])/g;

store this code in a file name: pcc (= Perl Colorize Character) and then put the file a in valid PATH then use it anywhere you like.

ls | pcc
df | pcc

inside mysql first register it for pager and then try:

[user2:db2] pager pcc
PAGER set to 'pcc'
[user2:db2] select * from table-name;

https://i.stack.imgur.com/UdRVk.png

It does NOT handle Unicode.

Do these codes only do colorizing?

No, they can do a lot of interesting things. Try:

echo -e '\033[2K'  # clear the screen and do not move the position

or:

echo -e '\033[2J\033[u' # clear the screen and reset the position

There are a lot of beginners that want to clear the screen with system( "clear" ) so you can use this instead of system(3) call

Are they available in Unicode?

Yes. \u001b

Which version of these colors is preferable?

https://raw.githubusercontent.com/k-five/badge-for-git/master/res/rgb/r/r-FF0000.svg?sanitize=true

reference:
Wikipedia
ANSI escape sequences
tldp.org
tldp.org
misc.flogisoft.com
some blogs/web-pages that I do not remember

You can use the awesome tput command (suggested in Ignacio's answer) to produce terminal control codes for all kinds of things.

Usage

Specific tput sub-commands are discussed later.

Direct

Call tput as part of a sequence of commands:

tput setaf 1; echo "this is red text"

Use ; instead of && so if tput errors the text still shows.

Shell variables

Another option is to use shell variables:

red=`tput setaf 1`
green=`tput setaf 2`
reset=`tput sgr0`
echo "${red}red text ${green}green text${reset}"

tput produces character sequences that are interpreted by the terminal as having a special meaning. They will not be shown themselves. Note that they can still be saved into files or processed as input by programs other than the terminal.

Command substitution

It may be more convenient to insert tput's output directly into your echo strings using command substitution:

echo "$(tput setaf 1)Red text $(tput setab 7)and white background$(tput sgr 0)"

Example

The above command produces this on Ubuntu:

https://i.stack.imgur.com/6tYnk.png

Foreground & background colour commands

tput setab [1-7] # Set the background colour using ANSI escape
tput setaf [1-7] # Set the foreground colour using ANSI escape

Colours are as follows:

Num  Colour    #define         R G B

0    black     COLOR_BLACK     0,0,0
1    red       COLOR_RED       1,0,0
2    green     COLOR_GREEN     0,1,0
3    yellow    COLOR_YELLOW    1,1,0
4    blue      COLOR_BLUE      0,0,1
5    magenta   COLOR_MAGENTA   1,0,1
6    cyan      COLOR_CYAN      0,1,1
7    white     COLOR_WHITE     1,1,1

There are also non-ANSI versions of the colour setting functions (setb instead of setab, and setf instead of setaf) which use different numbers, not given here.

Text mode commands

tput bold    # Select bold mode
tput dim     # Select dim (half-bright) mode
tput smul    # Enable underline mode
tput rmul    # Disable underline mode
tput rev     # Turn on reverse video mode
tput smso    # Enter standout (bold) mode
tput rmso    # Exit standout mode

Cursor movement commands

tput cup Y X # Move cursor to screen postion X,Y (top left is 0,0)
tput cuf N   # Move N characters forward (right)
tput cub N   # Move N characters back (left)
tput cuu N   # Move N lines up
tput ll      # Move to last line, first column (if no cup)
tput sc      # Save the cursor position
tput rc      # Restore the cursor position
tput lines   # Output the number of lines of the terminal
tput cols    # Output the number of columns of the terminal

Clear and insert commands

tput ech N   # Erase N characters
tput clear   # Clear screen and move the cursor to 0,0
tput el 1    # Clear to beginning of line
tput el      # Clear to end of line
tput ed      # Clear to end of screen
tput ich N   # Insert N characters (moves rest of line forward!)
tput il N    # Insert N lines

Other commands

tput sgr0    # Reset text format to the terminal's default
tput bel     # Play a bell

With compiz wobbly windows, the bel command makes the terminal wobble for a second to draw the user's attention.

Scripts

tput accepts scripts containing one command per line, which are executed in order before tput exits.

Avoid temporary files by echoing a multiline string and piping it:

echo -e "setf 7\nsetb 1" | tput -S  # set fg white and bg red

See also

See man 1 tput

See man 5 terminfo for the complete list of commands and more details on these options. (The corresponding tput command is listed in the Cap-name column of the huge table that starts at line 81.)

Use tput with the setaf capability and a parameter of 1.

echo "$(tput setaf 1)Hello, world$(tput sgr0)"

echo -e "\033[31m Hello World"

The [31m controls the text color:

30-37 sets foreground color

40-47 sets background color

A more complete list of color codes can be found here.

It is good practice to reset the text color back to \033[0m at the end of the string.

I have just amalgamated the good catches in all solutions and ended up with:

cecho(){
    RED="\033[0;31m"
    GREEN="\033[0;32m"  # <-- [0 means not bold
    YELLOW="\033[1;33m" # <-- [1 means bold
    CYAN="\033[1;36m"
    # ... Add more colors if you like

    NC="\033[0m" # No Color

    # printf "${(P)1}${2} ${NC}\n" # <-- zsh
    printf "${!1}${2} ${NC}\n" # <-- bash
}

And you can just call it as:

cecho "RED" "Helloworld"

https://i.stack.imgur.com/urVij.png

My riff on Tobias' answer:

# Color
RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[0;33m'
NC='\033[0m' # No Color

function red {
    printf "${RED}$@${NC}\n"
}

function green {
    printf "${GREEN}$@${NC}\n"
}

function yellow {
    printf "${YELLOW}$@${NC}\n"
}

https://i.stack.imgur.com/Nt7QJ.png

This is the color switch \033[. See history.

Color codes are like 1;32 (Light Green), 0;34 (Blue), 1;34 (Light Blue), etc.

We terminate color sequences with a color switch \033[ and 0m, the no-color code. Just like opening and closing tabs in a markup language.

  SWITCH="\033["
  NORMAL="${SWITCH}0m"
  YELLOW="${SWITCH}1;33m"
  echo "${YELLOW}hello, yellow${NORMAL}"

Simple color echo function solution:

cecho() {
  local code="\033["
  case "$1" in
    black  | bk) color="${code}0;30m";;
    red    |  r) color="${code}1;31m";;
    green  |  g) color="${code}1;32m";;
    yellow |  y) color="${code}1;33m";;
    blue   |  b) color="${code}1;34m";;
    purple |  p) color="${code}1;35m";;
    cyan   |  c) color="${code}1;36m";;
    gray   | gr) color="${code}0;37m";;
    *) local text="$1"
  esac
  [ -z "$text" ] && local text="$color$2${code}0m"
  echo "$text"
}

cecho "Normal"
cecho y "Yellow!"

Use tput to calculate color codes. Avoid using the ANSI escape code (e.g. \E[31;1m for red) because it's less portable. Bash on OS X, for example, does not support it.

BLACK=`tput setaf 0`
RED=`tput setaf 1`
GREEN=`tput setaf 2`
YELLOW=`tput setaf 3`
BLUE=`tput setaf 4`
MAGENTA=`tput setaf 5`
CYAN=`tput setaf 6`
WHITE=`tput setaf 7`

BOLD=`tput bold`
RESET=`tput sgr0`

echo -e "hello ${RED}some red text${RESET} world"

A neat way to change color only for one echo is to define such function:

function coloredEcho(){
    local exp=$1;
    local color=$2;
    if ! [[ $color =~ '^[0-9]$' ]] ; then
       case $(echo $color | tr '[:upper:]' '[:lower:]') in
        black) color=0 ;;
        red) color=1 ;;
        green) color=2 ;;
        yellow) color=3 ;;
        blue) color=4 ;;
        magenta) color=5 ;;
        cyan) color=6 ;;
        white|*) color=7 ;; # white or invalid color
       esac
    fi
    tput setaf $color;
    echo $exp;
    tput sgr0;
}

Usage:

coloredEcho "This text is green" green

Or you could directly use color codes mentioned in Drew's answer:

coloredEcho "This text is green" 2

I found Shakiba Moshiri's awesome answer while I was looking info on that topic… then I had an idea… and it ended up in a quite nice function extremely easy to use 😁
So I've to share it 😉

https://github.com/ppo/bash-colors

Usage: $(c <flags>) inside an echo -e or printf

 ┌───────┬─────────────────┬──────────┐   ┌───────┬─────────────────┬──────────┐
 │ Code  │ Style           │ Octal    │   │ Code  │ Style           │ Octal    │
 ├───────┼─────────────────┼──────────┤   ├───────┼─────────────────┼──────────┤
 │   -   │ Foreground      │ \033[3.. │   │   B   │ Bold            │ \033[1m  │
 │   _   │ Background      │ \033[4.. │   │   U   │ Underline       │ \033[4m  │
 ├───────┼─────────────────┼──────────┤   │   F   │ Flash/blink     │ \033[5m  │
 │   k   │ Black           │ ......0m │   │   N   │ Negative        │ \033[7m  │
 │   r   │ Red             │ ......1m │   ├───────┼─────────────────┼──────────┤
 │   g   │ Green           │ ......2m │   │   L   │ Normal (unbold) │ \033[22m │
 │   y   │ Yellow          │ ......3m │   │   0   │ Reset           │ \033[0m  │
 │   b   │ Blue            │ ......4m │   └───────┴─────────────────┴──────────┘
 │   m   │ Magenta         │ ......5m │
 │   c   │ Cyan            │ ......6m │
 │   w   │ White           │ ......7m │
 └───────┴─────────────────┴──────────┘

Examples:

echo -e "$(c 0wB)Bold white$(c) and normal"
echo -e "Normal text… $(c r_yB)BOLD red text on yellow background… $(c _w)now on
  white background… $(c 0U) reset and underline… $(c) and back to normal."

This question has been answered over and over again :-) but why not.

First using tput is more portable in modern environments than manually injecting ASCII codes through echo -E

Here's a quick bash function:

 say() {
     echo "$@" | sed \
             -e "s/\(\(@\(red\|green\|yellow\|blue\|magenta\|cyan\|white\|reset\|b\|u\)\)\+\)[[]\{2\}\(.*\)[]]\{2\}/\1\4@reset/g" \
             -e "s/@red/$(tput setaf 1)/g" \
             -e "s/@green/$(tput setaf 2)/g" \
             -e "s/@yellow/$(tput setaf 3)/g" \
             -e "s/@blue/$(tput setaf 4)/g" \
             -e "s/@magenta/$(tput setaf 5)/g" \
             -e "s/@cyan/$(tput setaf 6)/g" \
             -e "s/@white/$(tput setaf 7)/g" \
             -e "s/@reset/$(tput sgr0)/g" \
             -e "s/@b/$(tput bold)/g" \
             -e "s/@u/$(tput sgr 0 1)/g"
  }

Now you can use:

 say @b@green[[Success]] 

to get:

https://i.stack.imgur.com/apgkM.png

Notes on portability of tput

First time tput(1) source code was uploaded in September 1986

tput(1) has been available in X/Open curses semantics in 1990s (1997 standard has the semantics mentioned below).

So, it's (quite) ubiquitous.

Thanks to @k-five for this answer

declare -A colors
#curl www.bunlongheng.com/code/colors.png

# Reset
colors[Color_Off]='\033[0m'       # Text Reset

# Regular Colors
colors[Black]='\033[0;30m'        # Black
colors[Red]='\033[0;31m'          # Red
colors[Green]='\033[0;32m'        # Green
colors[Yellow]='\033[0;33m'       # Yellow
colors[Blue]='\033[0;34m'         # Blue
colors[Purple]='\033[0;35m'       # Purple
colors[Cyan]='\033[0;36m'         # Cyan
colors[White]='\033[0;37m'        # White

# Bold
colors[BBlack]='\033[1;30m'       # Black
colors[BRed]='\033[1;31m'         # Red
colors[BGreen]='\033[1;32m'       # Green
colors[BYellow]='\033[1;33m'      # Yellow
colors[BBlue]='\033[1;34m'        # Blue
colors[BPurple]='\033[1;35m'      # Purple
colors[BCyan]='\033[1;36m'        # Cyan
colors[BWhite]='\033[1;37m'       # White

# Underline
colors[UBlack]='\033[4;30m'       # Black
colors[URed]='\033[4;31m'         # Red
colors[UGreen]='\033[4;32m'       # Green
colors[UYellow]='\033[4;33m'      # Yellow
colors[UBlue]='\033[4;34m'        # Blue
colors[UPurple]='\033[4;35m'      # Purple
colors[UCyan]='\033[4;36m'        # Cyan
colors[UWhite]='\033[4;37m'       # White

# Background
colors[On_Black]='\033[40m'       # Black
colors[On_Red]='\033[41m'         # Red
colors[On_Green]='\033[42m'       # Green
colors[On_Yellow]='\033[43m'      # Yellow
colors[On_Blue]='\033[44m'        # Blue
colors[On_Purple]='\033[45m'      # Purple
colors[On_Cyan]='\033[46m'        # Cyan
colors[On_White]='\033[47m'       # White

# High Intensity
colors[IBlack]='\033[0;90m'       # Black
colors[IRed]='\033[0;91m'         # Red
colors[IGreen]='\033[0;92m'       # Green
colors[IYellow]='\033[0;93m'      # Yellow
colors[IBlue]='\033[0;94m'        # Blue
colors[IPurple]='\033[0;95m'      # Purple
colors[ICyan]='\033[0;96m'        # Cyan
colors[IWhite]='\033[0;97m'       # White

# Bold High Intensity
colors[BIBlack]='\033[1;90m'      # Black
colors[BIRed]='\033[1;91m'        # Red
colors[BIGreen]='\033[1;92m'      # Green
colors[BIYellow]='\033[1;93m'     # Yellow
colors[BIBlue]='\033[1;94m'       # Blue
colors[BIPurple]='\033[1;95m'     # Purple
colors[BICyan]='\033[1;96m'       # Cyan
colors[BIWhite]='\033[1;97m'      # White

# High Intensity backgrounds
colors[On_IBlack]='\033[0;100m'   # Black
colors[On_IRed]='\033[0;101m'     # Red
colors[On_IGreen]='\033[0;102m'   # Green
colors[On_IYellow]='\033[0;103m'  # Yellow
colors[On_IBlue]='\033[0;104m'    # Blue
colors[On_IPurple]='\033[0;105m'  # Purple
colors[On_ICyan]='\033[0;106m'    # Cyan
colors[On_IWhite]='\033[0;107m'   # White


color=${colors[$input_color]}
white=${colors[White]}
# echo $white



for i in "${!colors[@]}"
do
  echo -e "$i = ${colors[$i]}I love you$white"
done

Result

https://i.stack.imgur.com/QwVs1.png

Hope this image help you to pick your color for your bash :D

If you are using zsh or bash

black() {
    echo -e "\e[30m${1}\e[0m"
}

red() {
    echo -e "\e[31m${1}\e[0m"
}

green() {
    echo -e "\e[32m${1}\e[0m"
}

yellow() {
    echo -e "\e[33m${1}\e[0m"
}

blue() {
    echo -e "\e[34m${1}\e[0m"
}

magenta() {
    echo -e "\e[35m${1}\e[0m"
}

cyan() {
    echo -e "\e[36m${1}\e[0m"
}

gray() {
    echo -e "\e[90m${1}\e[0m"
}

black 'BLACK'
red 'RED'
green 'GREEN'
yellow 'YELLOW'
blue 'BLUE'
magenta 'MAGENTA'
cyan 'CYAN'
gray 'GRAY'

Try online

We can use 24 Bits RGB true colors for both text and background!

 ESC[38;2;⟨r⟩;⟨g⟩;⟨b⟩m  /*Foreground color*/
 ESC[48;2;⟨r⟩;⟨g⟩;⟨b⟩m  /*Background color*/

Example red text and closing tag:

 echo -e "\e[38;2;255;0;0mHello world\e[0m"

Generator:

text.addEventListener("input",update) back.addEventListener("input",update) function update(){ let a = text.value.substr(1).match(/.{1,2}/g) let b = back.value.substr(1).match(/.{1,2}/g) out1.textContent = "echo -e \"\\" + `033[38;2;${parseInt(a[0],16)};${parseInt(a[1],16)};${parseInt(a[2],16)}mHello\"` out2.textContent = "echo -e \"\\" + `033[48;2;${parseInt(b[0],16)};${parseInt(b[1],16)};${parseInt(b[2],16)}mWorld!\"` } div {padding:1rem;font-size:larger} TEXT COLOR:

echo -e "\033[31;7mHello world\e[0m";

for i in {30..49};do echo -e "\033[$i;7mReversed color code $i\e[0m Hello world!";done