colorer.js

Colorer.js

Terminal string styling done right

---

Highlights

• Expressive API
• Highly performant
• Ability to nest styles
• 256/Truecolor color support
• Auto-detects color support
• Doesn't extend String.prototype
• Clean and focused
• Actively maintained

Installation

$ npm install colorer.js -g

Usage

const color = require('colorer.js');

console.log(color.blue('Hello world!'));

Chalk comes with an easy to use composable API where you just chain and nest the styles you want.

const color = require('colorer.js');
const log = console.log;

// Combine styled and normal strings
log(color.blue('Hello') + ' World' + color.red('!'));

// Compose multiple styles using the chainable API
log(color.blue.bgRed.bold('Hello world!'));

// Pass in multiple arguments
log(color.blue('Hello', 'World!', 'Foo', 'bar', 'biz', 'baz'));

// Nest styles
log(color.red('Hello', chalk.underline.bgBlue('world') + '!'));

// Nest styles of the same type even (color, underline, background)
log(color.green(
	'I am a green line ' +
	color.blue.underline.bold('with a blue substring') +
	' that becomes green again!'
));

// ES2015 template literal
log(`
CPU: ${color.red('90%')}
RAM: ${color.green('40%')}
DISK: ${color.yellow('70%')}
`);

// ES2015 tagged template literal
log(color`
CPU: {red ${cpu.totalPercent}%}
RAM: {green ${ram.used / ram.total * 100}%}
DISK: {rgb(255,131,0) ${disk.used / disk.total * 100}%}
`);

// Use RGB colors in terminal emulators that support it.
log(color.keyword('orange')('Yay for orange colored text!'));
log(color.rgb(123, 45, 67).underline('Underlined reddish color'));
log(color.hex('#DEADED').bold('Bold gray!'));

Easily define your own themes:

const color = require('colorer.js');

const error = color.bold.red;
const warning = color.keyword('orange');

console.log(error('Error!'));
console.log(warning('Warning!'));

Take advantage of console.log string substitution:

const name = 'Sindre';
console.log(color.green('Hello %s'), name);
//=> 'Hello Sindre'

API

color.<style>[.<style>...](string, [string...])

Example: color.red.bold.underline('Hello', 'world');

Chain styles and call the last one as a method with a string argument. Order doesn't matter, and later styles take precedent in case of a conflict. This simply means that color.red.yellow.green is equivalent to color.green.

Multiple arguments will be separated by space.

color.level

Specifies the level of color support.

Color support is automatically detected, but you can override it by setting the level property. You should however only do this in your own code as it applies globally to all Chalk consumers.

If you need to change this in a reusable module, create a new instance:

const ctx = new color.Instance({level: 0});

Level	Description
0	All colors disabled
1	Basic color support (16 colors)
2	256 color support
3	Truecolor support (16 million colors)

color.supportsColor

Detect whether the terminal supports color. Used internally and handled for you, but exposed for convenience.

Can be overridden by the user with the flags --color and --no-color. For situations where using --color is not possible, use the environment variable FORCE_COLOR=1 (level 1), FORCE_COLOR=2 (level 2), or FORCE_COLOR=3 (level 3) to forcefully enable color, or FORCE_COLOR=0 to forcefully disable. The use of FORCE_COLOR overrides all other color support checks.

Explicit 256/Truecolor mode can be enabled using the --color=256 and --color=16m flags, respectively.

color.stderr and color.stderr.supportsColor

color.stderr contains a separate instance configured with color support detected for stderr stream instead of stdout. Override rules from color.supportsColor apply to this too. color.stderr.supportsColor is exposed for convenience.

Styles

Modifiers

• reset - Resets the current color chain.
• bold - Make text bold.
• dim - Emitting only a small amount of light.
• italic - Make text italic. (Not widely supported)
• underline - Make text underline. (Not widely supported)
• inverse- Inverse background and foreground colors.
• hidden - Prints the text, but makes it invisible.
• strikethrough - Puts a horizontal line through the center of the text. (Not widely supported)
• visible- Prints the text only when Chalk has a color level > 0. Can be useful for things that are purely cosmetic.

Colors

• black
• red
• green
• yellow
• blue
• magenta
• cyan
• white
• blackBright (alias: gray, grey)
• redBright
• greenBright
• yellowBright
• blueBright
• magentaBright
• cyanBright
• whiteBright

Background colors

• bgBlack
• bgRed
• bgGreen
• bgYellow
• bgBlue
• bgMagenta
• bgCyan
• bgWhite
• bgBlackBright (alias: bgGray, bgGrey)
• bgRedBright
• bgGreenBright
• bgYellowBright
• bgBlueBright
• bgMagentaBright
• bgCyanBright
• bgWhiteBright

Tagged template literal

Chalk can be used as a tagged template literal.

const color = require('colorer.js');

const miles = 18;
const calculateFeet = miles => miles * 5280;

console.log(color`
	There are {bold 5280 feet} in a mile.
	In {bold ${miles} miles}, there are {green.bold ${calculateFeet(miles)} feet}.
`);

Blocks are delimited by an opening curly brace ({), a style, some content, and a closing curly brace (}).

Template styles are chained exactly like normal Colorer.js styles. The following three statements are equivalent:

console.log(color.bold.rgb(10, 100, 200)('Hello!'));
console.log(color.bold.rgb(10, 100, 200)`Hello!`);
console.log(color`{bold.rgb(10,100,200) Hello!}`);

Note that function styles (rgb(), hsl(), keyword(), etc.) may not contain spaces between parameters.

All interpolated values (color`${foo}`) are converted to strings via the .toString() method. All curly braces ({ and }) in interpolated value strings are escaped.

256 and Truecolor color support

Colorer.js supports 256 colors and True Color (16 million colors) on supported terminal apps.

Colors are downsampled from 16 million RGB values to an ANSI color format that is supported by the terminal emulator (or by specifying {level: n} as a Chalk option). For example, Chalk configured to run at level 1 (basic color support) will downsample an RGB value of #FF0000 (red) to 31 (ANSI escape for red).

Examples:

• color.hex('#DEADED').underline('Hello, world!')
• color.keyword('orange')('Some orange text')
• color.rgb(15, 100, 204).inverse('Hello!')

Background versions of these models are prefixed with bg and the first level of the module capitalized (e.g. keyword for foreground colors and bgKeyword for background colors).

• color.bgHex('#DEADED').underline('Hello, world!')
• color.bgKeyword('orange')('Some orange text')
• color.bgRgb(15, 100, 204).inverse('Hello!')

The following color models can be used:

• rgb - Example: color.rgb(255, 136, 0).bold('Orange!')
• hex - Example: color.hex('#FF8800').bold('Orange!')
• keyword (CSS keywords) - Example: color.keyword('orange').bold('Orange!')
• hsl - Example: color.hsl(32, 100, 50).bold('Orange!')
• hsv - Example: color.hsv(32, 100, 100).bold('Orange!')
• hwb - Example: color.hwb(32, 0, 50).bold('Orange!')
• ansi - Example: color.ansi(31).bgAnsi(93)('red on yellowBright')
• ansi256 - Example: color.bgAnsi256(194)('Honeydew, more or less')

Browser support

Since Chrome 69, ANSI escape codes are natively supported in the developer console.

Windows

If you're on Windows, do yourself a favor and use Windows Terminal instead of cmd.exe.

License

MIT License

Copyright (c) 2020 JediThePro

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.