How to change node.js's console font color?
Question
I had to change the console background color to white because of eye problems, but the font is gray colored and it makes the messages unreadable. How can I change it?
Accepted Answer
Below you can find colors reference of text to command when running node.js application:
console.log('\x1b[36m%s\x1b[0m', 'I am cyan'); //cyan
console.log('\x1b[33m%s\x1b[0m', stringToMakeYellow); //yellow
Note %s
is where in the string (the second argument) gets injected. \x1b[0m
resets the terminal color so it doesn't continue to be the chosen color anymore after this point.
Colors reference
Reset = "\x1b[0m"
Bright = "\x1b[1m"
Dim = "\x1b[2m"
Underscore = "\x1b[4m"
Blink = "\x1b[5m"
Reverse = "\x1b[7m"
Hidden = "\x1b[8m"
FgBlack = "\x1b[30m"
FgRed = "\x1b[31m"
FgGreen = "\x1b[32m"
FgYellow = "\x1b[33m"
FgBlue = "\x1b[34m"
FgMagenta = "\x1b[35m"
FgCyan = "\x1b[36m"
FgWhite = "\x1b[37m"
BgBlack = "\x1b[40m"
BgRed = "\x1b[41m"
BgGreen = "\x1b[42m"
BgYellow = "\x1b[43m"
BgBlue = "\x1b[44m"
BgMagenta = "\x1b[45m"
BgCyan = "\x1b[46m"
BgWhite = "\x1b[47m"
EDIT:
For example, \x1b[31m
is an escape sequence that will be intercepted by your terminal and instructs it to switch to the red color. In fact, \x1b
is the code for the non-printable control character escape
. Escape sequences dealing only with colors and styles are also known as ANSI escape code and are standardized, so therefore they (should) work on any platform.
Wikipedia has a nice comparison of how different terminals display colors https://en.wikipedia.org/wiki/ANSI_escape_code#Colors
Popular Answer
There are multiple packages available for formatting console text in Node.js. The most popular are:
Usage:
CHALK:
const chalk = require('chalk');
console.log(chalk.red('Text in red'));
CLI-COLOR:
const clc = require('cli-color');
console.log(clc.red('Text in red'));
COLORS:
const colors = require('colors');
console.log('Text in red'.red);
Many people have noted their disapproval of colors
altering the String prototype. If you prefer your prototypes to be left alone, use the following code instead:
const colors = require('colors/safe');
console.log(colors.red('Text in red'));
Read more... Read less...
If you want to change the colors directly yourself without a module try
console.log('\x1b[36m', 'sometext' ,'\x1b[0m');
First \x1b[36m
to change the colors to 36
and then back to terminal color 0
.
to color your output You can use examples from there:
https://help.ubuntu.com/community/CustomizingBashPrompt
Also a Gist for nodeJs
For example if you want part of the text in red color, just do console.log with:
"\033[31m this will be red \033[91m and this will be normal"
Based on that I've created "colog" extension for Node.js. You can install it using:
npm install colog
Repo and npm: https://github.com/dariuszp/colog
This is a list of available colors (background,foreground) in console with available actions (reset,reverse,...).
const colors = {
Reset: "\x1b[0m",
Bright: "\x1b[1m",
Dim: "\x1b[2m",
Underscore: "\x1b[4m",
Blink: "\x1b[5m",
Reverse: "\x1b[7m",
Hidden: "\x1b[8m",
fg: {
Black: "\x1b[30m",
Red: "\x1b[31m",
Green: "\x1b[32m",
Yellow: "\x1b[33m",
Blue: "\x1b[34m",
Magenta: "\x1b[35m",
Cyan: "\x1b[36m",
White: "\x1b[37m",
Crimson: "\x1b[38m" //القرمزي
},
bg: {
Black: "\x1b[40m",
Red: "\x1b[41m",
Green: "\x1b[42m",
Yellow: "\x1b[43m",
Blue: "\x1b[44m",
Magenta: "\x1b[45m",
Cyan: "\x1b[46m",
White: "\x1b[47m",
Crimson: "\x1b[48m"
}
};
Use it as following :
console.log(colors.bg.Blue, colors.fg.White , "I am white message with blue background", colors.Reset) ;
//don't forget "colors.Reset" to stop this color and return back to the default color
You can also install :
npm install console-info console-warn console-error --save-dev
IT will give you an output closer to console of client side :
Per this documentation, you can change the colors based on the data type of the output:
// you'll need the util module
var util = require('util');
// let's look at the defaults:
util.inspect.styles
{ special: 'cyan',
number: 'yellow',
boolean: 'yellow',
undefined: 'grey',
null: 'bold',
string: 'green',
date: 'magenta',
regexp: 'red' }
// what are the predefined colors?
util.inspect.colors
{ bold: [ 1, 22 ],
italic: [ 3, 23 ],
underline: [ 4, 24 ],
inverse: [ 7, 27 ],
white: [ 37, 39 ],
grey: [ 90, 39 ],
black: [ 30, 39 ],
blue: [ 34, 39 ],
cyan: [ 36, 39 ],
green: [ 32, 39 ],
magenta: [ 35, 39 ],
red: [ 31, 39 ],
yellow: [ 33, 39 ] }
These appear to be ANSI SGR escape codes, where the first number is the code to emit before the output, and the second number is the code to emit after. So if we look at the chart of ANSI SGR codes on Wikipedia, you'll see that most of these start with a number 30-37 to set the foreground color, and end in 39 to reset to the default foreground color.
So one thing I don't like is how dark some of these are. Especially dates. Go ahead and try new Date()
in the console. Dark magenta on black is really hard to read. Let's change that to a light magenta instead.
// first define a new color
util.inspect.colors.lightmagenta = [95,39];
// now assign it to the output for date types
util.inspect.styles.date = 'lightmagenta';
Now when you try new Date()
, the output is much more readable.
If you'd like to set colors automatically when launching node, create a script that launches the repl, like this:
// set your colors however desired
var util = require('util');
util.inspect.colors.lightmagenta = [95,39];
util.inspect.styles.date = 'lightmagenta';
// start the repl
require('repl').start({});
Save this file (for example, init.js
), then run node.exe init.js
. It will set the colors and launch the node.js command prompt.
(Thanks to loganfsmyth in this answer for the repl idea.)
Reset: "\x1b[0m"
Bright: "\x1b[1m"
Dim: "\x1b[2m"
Underscore: "\x1b[4m"
Blink: "\x1b[5m"
Reverse: "\x1b[7m"
Hidden: "\x1b[8m"
FgBlack: "\x1b[30m"
FgRed: "\x1b[31m"
FgGreen: "\x1b[32m"
FgYellow: "\x1b[33m"
FgBlue: "\x1b[34m"
FgMagenta: "\x1b[35m"
FgCyan: "\x1b[36m"
FgWhite: "\x1b[37m"
BgBlack: "\x1b[40m"
BgRed: "\x1b[41m"
BgGreen: "\x1b[42m"
BgYellow: "\x1b[43m"
BgBlue: "\x1b[44m"
BgMagenta: "\x1b[45m"
BgCyan: "\x1b[46m"
BgWhite: "\x1b[47m"
For example if you want to have a Dim, Red text with Blue background you can do it in Javascript like this:
console.log("\x1b[2m", "\x1b[31m", "\x1b[44m", "Sample Text", "\x1b[0m");
The order of the colors and effects seems to not be that important but always remember to reset the colors and effects at the end.