This is the README for a package I recently published on NPM. It's not really meant to be a blog post. I was mostly curious what it would look like with the styles I currently have set for my site. But if you're reading this and are curious about it, give it a try and let me know what you think. Ok... now back to the README.

A lightweight library for color validation, manipulation, conversion, theme and palette generation

Installation

Color Tools is available on Npm. You can install it using the package manager of your choice.

# NPM
npm install @mattbrannon/color-tools

# Yarn
yarn add @mattbrannon/color-tools

# Pnpm
pnpm add @mattbrannon/color-tools

Usage

This package uses named exports and supports both CommonJS and ESModules.

ES Modules

import { Color, Theme, convert } from '@mattbrannon/color-tools'

Common JS

const { Color, Theme, convert } = require('@mattbrannon/color-tools')

Color

The Color class utility is versatile. It is able to convert between hexadecimal, rgb, and hsl color spaces. Alpha channels are supported as well. It accepts any valid (and quite a few invalid) css color strings. In most cases operators like deg and % are not necessary. For hsl colors, deg and % will be assumed unless another operator is supplied.

const deepSkyBlue = new Color('deepskyblue')
const blue = new Color('rgb(0 0 255)')
const magenta = new Color('hsl(300 100 50 1)') // look ma! no commas
const brown = new Color('654321') // look ma! no # sign

Objects are also acceptable input. Objects should be in the form of

// the alpha `a` channel is optional
new Color({ r, g, b, a })
new Color({ h, s, l, a })

The values for each color channel can be raw numbers or percentage strings

new Color({ r: '25%', g: 200, b: 100, a: '90%' })
new Color({ h: 270, s: 100, l: '50%', a: 0.75 })

You can use an array for input as well with one caveat. When supplying an array of values as input, you must also supply a configuration object as a second argument. Otherwise, it's impossible to know which color space the values belong to.

Config

// using an array we need to specify the initial color space
// we can still set the preferred data type to whatever we choose
const green = new Color([0, 128, 0], {
  colorSpace: 'rgb',
  dataType: {},
})

green.value() // { r:0, g:128, b:0 }

// here we don't need to set a color space to be able to parse the input
// instead we're setting a color space to use as the default for this color
const deepPink = new Color('deeppink', {
  colorSpace: 'hsl',
  dataType: [],
})

deepPink.value() // [328, 100, 54]

Color Spaces

The available color spaces currently include rgb, hsl, hex

Each color space has the following methods for specifying the output datatype

• array()
• object()
• css()

The syntax for each color space method is

color.<color-space>.<method>

For example:

const color = new Color('deepskyblue')

// HSL colors
color.hsl.css() // hsl(195deg, 100%, 50%)
color.hsl.object() // {h:195, s:100, l:50}
color.hsl.array() // [195, 100, 50]

// RGB colors
color.rgb.css() // rgb(0, 191, 255)
color.rgb.object() // {r:0, g:191, b:255}
color.rgb.array() // [0, 191, 255]

// HEX colors
color.hex.css() // '#00bfff'
color.hex.object() // {r:'00', g:'bf', b:'ff'};
color.hex.array() // ['00', 'bf', 'ff']

Color Methods

The methods listed below are globally available per instance of Color. There's no need to target a specific color space.

• value() A convenience method that returns the current instance's color value based on the preferred color space and data types
• contrast() Returns the contrast ratio between the current color instance and another color. accepts the same input parameters as Color minus the config
• luminance() Returns a floating point number between 0 and 1 representing the color's luminance value
• red() set the red rgb channel
• green() set the green rgb channel
• blue() set the blue rgb channel
• hue() set the hsl hue value
• saturation() set the hsl saturation value
• lightness() set the hsl lightness value

Value

The simplest way to obtain the color output is with the value method. The output of this method will vary depending on the input and configuration provided.

For named colors, without a configuration, the default output will be in hexadecimal format. For all other inputs without a config, the output of value will directly match the input.

// named colors default to hex format
const blue = new Color('blue')
blue.value() // '#0000FF'

const red = new Color('rgb(255 0 0)')
red.value() // 'rgb(255, 0, 0)'

const green = new Color({ h: 120, s: 100, l: 25 })
green.value() // {h:120, s:100, l:25}

Contrast

Get the contrast ratio between the current color and another. Accepts the same input formats as Color

const orange = new Color('orange')
const ratio = orange.contrast('red') // 2.02

Luminance

Get the relative luminance value of the current color Returns a value between 0 - 1 with 0 being total darkness and 1 being all white

new Color('#8faba2').luminance() // 0.3757409455965292

RGB Methods

Set the value for red, green or blue channels. Values will be converted to rgb to make the adjustment and then converted back to the current color space (if necessary).

const black = new Color('#000')
const pureRed = black.red(255)
const magenta = pureRed.blue(255)
const purple = magenta.red(-127).blue(-127)
const grey = magenta.red(-127).blue(-127).green(127)

HSL Methods

Set the value for hue, saturation or lightness. Values will be converted to hsl to make the adjustment and then converted back to the current color space (if necessary).

const black = new Color('#000')
const maroon = black.saturation(100).lightness(25)
const purple = maroon.hue(300)

Static Methods

• Color.random() - returns a random hexadecimal color value
• Color.contrast() - Takes 2 colors as input and returns the contrast ratio between them.

const randomColor = Color.random() // #0d7ae8

const ratio = Color.contrast('orange', 'red') // 2.02

Theme

Theme is an extension of Color and has some useful methods for generating color palettes.

The output will be an array of strings based on the input color space.

The color palettes provided will be uniform in their levels of saturation and lightness. More than likely you'll want to tweak these a bit when deciding which colors to use.

Theme Methods

• complementary()
• compound()
• analagous()
• triadic()
• rectangle()
• square()

Complementary

A complementary color palette is one which consists of two colors opposite each other on the color wheel.

new Theme('hsl(0 100 50)').complementary()
/*
[
  'hsl(0deg, 100%, 50%)', 
  'hsl(180deg, 100%, 50%)'
]
*/

Compound

Similar to complementary but generates 3 colors. The base color provided as input and then the 2 colors on either side of the base complementary color. This is also known as splitComplementary

new Theme('rgb(255 0 0)').compound()
/*
[
  'rgb(0, 127, 255)', 
  'rgb(255, 0, 0)', 
  'rgb(0, 255, 128)'
]
*/

Analagous

An analagous color palette is one in which three colors are positioned next to each other on the color wheel.

new Theme('hsl(240 100 50)').analagous()
/*
[
  'hsl(210deg, 100%, 50%)', 
  'hsl(240deg, 100%, 50%)', 
  'hsl(270deg, 100%, 50%)'
]
*/

Triadic

A triadic color palette is one which consists of three colors evenly spaced on the color wheel.

new Theme('rgb(255 0 0)').triadic()
/*
[
  'rgb(0, 0, 255)', 
  'rgb(255, 0, 0)', 
  'rgb(0, 255, 0)'
]
*/

Rectangle

A rectangle color palette is one which consists of four colors grouped in pairs of complementary colors. Drawing a line through to each color on the color wheel forms the shape of a rectangle. This is also known as a tetradic color palette

new Theme('rgb(255 0 0)').rectangle()
/*
[
  'rgb(255, 0, 0)', 
  'rgb(0, 255, 0)', 
  'rgb(0, 255, 255)', 
  'rgb(255, 0, 255)'
]
*/

Square

A square color palette is one in which all four colors are at an equal distance on the color wheel

new Theme('hsl(0 100 50)').square()
/*
[
  'hsl(0deg, 100%, 50%)', 
  'hsl(90deg, 100%, 50%)', 
  'hsl(180deg, 100%, 50%)', 
  'hsl(270deg, 100%, 50%)'
]
*/