Basic

Use ANSI codes escaped as \e[CODEm where CODE is an ANSI code.

You must use the -e flag and also double quotes.

echo -e "\e[31mHello, world"
# Reset.
echo -e "\e[31mHello, world\e[0m"
# Change styles.
echo -e "\e[31mHello, \e[0m\e[1mworld"
# Set text and background colors.
echo -e "\e[33m\e[42mHello, world"

When to reset:

  • You don’t have to use a reset code at the end when using the terminal. The next echo will be back to normal.

  • But when running multiple prints in a script, you do need to reset otherwise you’ll keep the style. Or use this to your advantage - set the color on the initial echo and then only reset a couple lines down.

Reuse

As a function. Use one quoted string or multiple unquoted words.

warn() {
  echo -e "\e[31m$@\e[0m"
}

warn 'This text will be red'
# => This text will be red

As an alias. This seems to include a leading space.

alias warn='echo -e "\e[31m"'
warn 'This text will be red'
# =>  This text will be red

Mapping

Note that Normal can remove bold and dim but not colors, while Reset can remove both.

Style Code
Reset 0
Normal 22
Bold 1
Dim 2
Underline on 4
Underline off 24
Blink start 5
Blink end 25
Inverse pallete start 7
Inverse pallete end 27
Conceal 8
Color Text code Background code
Black 30 40
Red 31 41
Green 32 42
Yellow 33 43
Blue 34 44
Magenta 35 45
Cyan 36 46
Light Grey 37 47