Bash scripts are very easy way to get things automated, and there are plenty of features to interact with the users. Apart from interacting you can also convey the information using colors. Just like this.
For getting colors in echo command, you need to give escape sequence which tells the terminal to listen to a command to change the property of the terminal. For that you need to enable it using the parameter -e. Now to tell the terminal that we need to change the color, we have to send the command octal 033 or hexadecimal 0x1b. For more information refer https://en.wikipedia.org/wiki/ANSI_escape_code .
echo -e "\033[31m Hello World"
The above example will change the text color in to red. 30-37 sets foreground color , 40-47 sets background color. Now you can write scripts like to make the work easier.
ESC_SEQ="\x1b[" COL_RESET=$ESC_SEQ"39;49;00m" COL_RED=$ESC_SEQ"31;01m" COL_GREEN=$ESC_SEQ"32;01m" COL_YELLOW=$ESC_SEQ"33;01m" COL_BLUE=$ESC_SEQ"34;01m" COL_MAGENTA=$ESC_SEQ"35;01m" COL_CYAN=$ESC_SEQ"36;01m" echo -e "$COL_RED This is yellow $COL_RESET" echo -e "$COL_BLUE This is red $COL_RESET" echo -e "$COL_YELLOW This is blue $COL_RESET"
The COL_RESET=$ESC_SEQ”39;49;00m” , will reset the previously set property of the terminal and set it to default.
For more information check out the following links,