Color utilities

Collection of useful methods for colors parsing, validation, transformations and calculations. Exposed as a class, so can be used as a stand-alone, or inside Angular apps.

Install and use

npm install @kolory/color-utilities

Use in a JavaScript or TypeScript project:

// TypeScript, JavaScript module
import {ColorUtilities} from '@kolory/color-utilities'

// Node, Browserify
const ColorUtilities = require('@kolory/color-utilities')

// Create using a `new` keyword or with a factory (preferred).
const colorUtilitiesFromFactory = ColorUtilities.create() // Preferred.
const colorUtilities = new ColorUtilities()

Library is compatible with the Angular 2 dependency injection system. Provide it as a dependency in a Component or NgModule decorator.

@Component({
  ...
  providers: [ColorUtilities, ...]
})
class MyComponent {
  consturctor(private colorUtilities: ColorUtilities) {}
}

Features

Converters

Convert a color to another format

#convert(color: basicColor, to: ColorTypes | 'hex' | 'rgb' | 'hsl'): basicColor
#convertToHex(color: basicColor): basicColor
#convertToRgb(color: basicColor): basicColor
#convertToHsl(color: basicColor): basicColor

Converts a color into a different format (eg. hex to RGB or HSL to hex). Use either the generic convert method providing a color to be converted with the outcome format (from the ColorType enum or as a string) or one of the specific method .

Parameters

color - A valid color that will be converted. to - (in the #convert generic method) a color type (coming from the ColorTypes enum) into which the color should be converted.

Returns

A valid color in another format.

Example

import {ColorTypes} from '@kolory/color-utilities'
colorUtilities.convert('#F03402', ColorTypes.hsl) // => 'hsl(13, 98%, 47%)'
colorUtilities.convert('hsl(39, 100%, 50%)', ColorTypes.rgb) // => 'rgb(255, 166, 0)'
colorUtil.convertToRgb('#FFA500') // => 'rgb(255, 165, 0)'
colorUtil.convertToHsl('rgb(255, 166, 0)') // => 'hsl(39, 100%, 50%)'
colorUtil.convertToHex('hsl(39, 100%, 50%)') // => '#FFA600'

Convert a raw color values to the color format

#convertRawValuesTo(values: colorValues, to: ColorTypes): basicColor

Converts a raw color values (a triplet array: [R, G, B]) into a formatted string (eg. hex to RGB or HSL to hex).

Parameters

values - A raw values. to - a color type (coming from the ColorTypes enum) into which the color should be converted.

Returns

A valid color in another format.

Example

colorUtilities.convertRawValuesTo([255, 165, 0], ColorTypes.hex) // => '#FFA500'

Parsers

Parse any color

#parseColor(color: basicColor): colorValues

Transforms RGB, HSL or hex color into an array of RGB values. A generic variant of specific parsers dedicated for hex and RGB colors.

Parameters

color - A color in RGB, HSL or hex format to be parsed.

Returns

An array representation of the provided number. Throws if an invalid color was used (use validators methods id unsure if the value will always be correct).

Example

colorUtilities.parseColor('#FFAA500') // => [255, 165, 0]
colorUtilities.parseColor('#fff') // => [255, 255, 255]
colorUtilities.parseColor('rgb(255, 165, 0)') // => [255, 165, 0]
colorUtilities.parseColor('rgb(255, 255, 255)') // => [255, 255, 255]
colorUtilities.parseColor('hsl(0, 100%, 100%)') // => [255, 255, 255]

Parse a hexadecimal color

#parseHexColor(color: hexColor): colorValues

Transforms a hexadecimal color into an array of RGB values in base-10.

Parameters

color - A hexadecimal color (eg. '#FFA500'). Shorthand notation ('#FFF') and small caps are also supported.

Returns

An array representation of the provided number. Throws if an invalid hex was used (use validators methods id unsure if the value will always be correct).

Examples

colorUtilities.parseHexColor('#FFAA500') // => [255, 165, 0]
colorUtilities.parseHexColor('#fff') // => [255, 255, 255]

Parse an RGB color

#parseRgbColor(color: RGBColor): colorValues

Transforms an RGB color into an array of RGB values.

Parameters

color - An RGB color (eg. 'rgb(255, 265, 0)').

Returns

An array representation of the provided number. Throws if an invalid RGB format was used (use validators methods id unsure if the value will always be correct).

Examples

colorUtilities.parseHexColor('rgb(255, 165, 0)') // => [255, 165, 0]
colorUtilities.parseHexColor('rgb(255, 255, 255)') // => [255, 255, 255]

Parse an HSL color

#parseHslColor(color: HSLColor): colorValues

Transforms an HSL color into an array of RGB values.

Parameters

color - An HSL color (eg. 'hsl(123, 45%, 0%)').

Returns

An array representation of the provided number. Throws if an invalid HSL format was used (use validators methods id unsure if the value will always be correct).

Examples

colorUtilities.parseHslColor('hsl(123, 100%, 100%)') // => [255, 255, 255]

Validators

Validate a color

#isValidColor(potentialColor?: basicColor): boolean

Checks if the provided color is a valid hexadecimal color, an RGB color or an HSL color. Uses specific validators internally, so the edge cases from them applies here.

Parameters

color - A color to be validated.

Returns

A boolean indicating validity of the color. For clarity sake: true means the color is valid.

Examples

colorUtilities.isValidColor('#FFA500') // => true 
colorUtilities.isValidColor('rgb(255, 165, 0)') // => true
colorUtilities.isValidColor('hsl(200, 100%, 50%)') // => true
colorUtilities.isValidColor('#QWERTY') // => false 
colorUtilities.isValidColor('#123456789') // => false
colorUtilities.isValidColor(null) // => false

Validate a hexadecimal color

#isValidHexColor(potentialHexColor?: hexColor): boolean

Checks if the provided color is a valid hexadecimal color.

Parameters

color - A hexadecimal color (eg. '#FFA500'). Shorthand notation ('#FFF') and small caps are also supported.

Returns

A boolean indicating validity of the color. For clarity sake: true means the color is valid.

Examples

colorUtilities.isValidHexColor('#FFA500') // => true 
colorUtilities.isValidHexColor('#fff') // => true
colorUtilities.isValidHexColor('#QWERTY') // => false 
colorUtilities.isValidHexColor('#123456789') // => false
colorUtilities.isValidHexColor(null) // => false

Validate an RGB color

#isValidRgbColor(potentialRgbColor?: RGBColor): boolean

Checks if the provided color is a valid RGB color.

Parameters

color - An RGB color (eg. 'rgb(255, 165, 0)').

Returns

A boolean indicating validity of the color. For clarity sake: true means the color is valid.

Examples

colorUtilities.isValidRgbColor('rgb(0, 0, 0)') // => true 
colorUtilities.isValidRgbColor('rgb(255, 165, 0') // => true
colorUtilities.isValidRgbColor('xrgb(255, 255, 255') // => false 
colorUtilities.isValidRgbColor('rgb(300, 300, 300') // => false
colorUtilities.isValidRgbColor(null) // => false

Validate an HSL color

#isValidHslColor(potentialHslColor?: HSLColor): boolean

Checks if the provided color is a valid HSL color.

Parameters

color - An HSL color (eg. 'hsl(300, 50%, 50%)').

Returns

A boolean indicating validity of the color. For clarity sake: true means the color is valid.

Examples

colorUtilities.isValidHslColor('hsl(123, 100%, 10%)') // => true 
colorUtilities.isValidHslColor('hsl(255, 1%, 40%') // => true
colorUtilities.isValidHslColor('xhsl(255, 255, 255') // => false 
colorUtilities.isValidHslColor('hsl(400, 50%, 50%') // => false
colorUtilities.isValidHslColor('hsl(100, 50, 50') // => false
colorUtilities.isValidHslColor(null) // => false

Analyzers

Get the hexadecimal color's parts

#splitHexColor(color: hexColor): hexColorValues

Splits the hexadecimal color into an array of it's hexadecimal RGB values.

Parameters

color - A hexadecimal color (eg. '#FFA500'). Shorthand notation ('#FFF') and small caps are also supported. The return value is always normalized to uppercase two letters/numbers long values.

Returns

The result of this method is a 3 items long array of hexadecimal RGB values.

Examples

colorUtilities.splitHexColor('#FFA500') // => ['FF', 'A5', '00']
colorUtilities.splitHexColor('#fff') // => ['FF', 'FF', 'FF']

Get the RGB color's parts

#splitRgbColor(color: RGBColor): colorValues

Splits the RGB color into an array of it's RGB values.

Parameters

color - An RGB color (eg. 'rgb(255, 165, 0)').

Returns

The result of this method is a 3 items long array of RGB values.

Examples

colorUtilities.splitRgbColor('rgb(255, 165, 0)') // => [255, 165, 0]
colorUtilities.splitRgbColor('rgb(255, 255, 255)') // => [255, 255, 255]

Get the HSL color's parts

#splitHslColor(color: HSLColor): colorValues

Splits the HSL color into an array of it's RGB values.

Parameters

color - An HSL color (eg. 'hsl(123, 10%, 50%)').

Returns

The result of this method is a 3 items long array of RGB values.

Examples

colorUtilities.splitHslColor('hsl(39, 100%, 50%)') // => [255, 166, 0]
colorUtilities.splitHslColor('hsl(0, 100%, 100%)') // => [255, 255, 255]

Normalizers

Normalize a hexadecimal color value

#normalizeHexColor(hexColor: hexColor): hexColor

Transforms a valid hex color into a uniform shape: 6 uppercased characters.

Parameters

color - A valid hex color that might be written in a shorthand notation or in lower case. As a bonus, this method considers the colors without initial '#' as semi-valid and adds the missing sign (validation still reports it's not a valid color).

Returns

A valid, 6 characters long (7 with '#') string of uppercased letters and numbers.

Examples

colorUtilities.normalizeHexColor('#fff') // => '#FFFFFF'

Normalize an RGB color value

#normalizeRgbColor(rgbColor: RGBColor): RGBColor

Transforms a valid RGB color into a uniform shape (lowercased with consistent spacing).

Parameters

color - A valid RGB color.

Returns

A valid, lowercased color string with consistent spacing.

Examples

colorUtilities.normalizeRgbColor('  RGB (  123,      123,1  )') // => 'rgb(123, 123, 1)

Normalize an HSL color value

#normalizeHslColor(hslColor: HSLColor): HSLColor

Transforms a valid HSL color into a uniform shape (lowercased with consistent spacing).

Parameters

color - A valid HSL color.

Returns

A valid, lowercased color string with consistent spacing.

Examples

colorUtilities.normalizeHslColor('  HSL (  123,      100%,1%  )') // => 'hsl(123, 100%, 1%)

Utilities

Calculate luminance of a color

#calculateLuminanceOf(color: basicColor): number

Calculates the relative luminance of a color, as defined in the W3C Specification.

Parameters

color - A valid color.

Returns

A number representing the relative luminance in [0-1] range.

Examples

colorUtilities.calculateLuminanceOf('#FFFFFF') // => 1
colorUtilities.calculateLuminanceOf('rgb(255, 255, 255)') // => 1
colorUtilities.calculateLuminanceOf('hsl(100, 100%, 100%)') // => 1
colorUtilities.calculateLuminanceOf('#000000') // => 0
colorUtilities.calculateLuminanceOf('#FFA500') // => 0.48170267036309633

Calculate contrast between two colors

#calculateContrastRatio(color1: basicColor, color2: basicColor): number

Calculates a contrast ratio between two colors, as defined in the W3C Specification.

Parameters

color1 - A valid color. color2 - A valid color.

Returns

A contrast between the provided colors. The value is in range [1-21].

Examples

colorUtilities.calculateContrastRatio('#FFFFFF', '#000000') // => 21
colorUtilities.calculateContrastRatio('rgb(255, 255, 255)', 'rgb(0, 0, 0)') // => 21
colorUtilities.calculateContrastRatio('#000000', '#000000') // => 1
colorUtilities.calculateContrastRatio('#FFA500', '#000000') // => 11
colorUtilities.calculateContrastRatio('hsl(100, 100%, 100%)', '#000000') // => 21

Color object

An object designed to abstract the color's formatting to make it easier to work with in different scenarios.

Creation

The Color object can be created by using the factory method. While the typical class instantation with a new keyword is supported and is functionally equivalent, it's discouraged as not future proof. Whenever you can, prever Color.create() over new Color().

The creating method can optionally be provided with a raw color value (RGB, HEX, HSL) or with another Color object. In the second case, the provided object is returned. When used without any color, the default white is used.

const red = Color.create('#FF0000')
const green = Color.create('#00FF00')
const blue = Color.create(0, 0, 255)

// Discouraged, but functionally equivalent.
const black = new Color('#000')

The Color class exposes predefined basic colors that can be used instead of providing their values.

const black = Color.black
const white = Color.white
const red = Color.red
const green = Color.green
const blue = Color.blue

Static methods

Create a Color object

Color.create(color?: anyColor): Color

Creates a new color object (a factory method). Refer to the "Creation" section for more information.

Check if an object is of the Color type

Color.isColor(color?: anyColor): boolean

Tests if the provided color is a Color object.

Parameters

color - Color or an object to be tested.

Returns

A boolean informing if the object or color is a Color object.

Examples

Color.isColor(new Color('#FFFFFF') // => true
Color.isColor('#FFFFFF') // => false

Properties

Color object exposes properties about the color value and allow accessing different formatting of that color.

color.hex // => string: color as a hex
color.rgb // => string: color in the RGB format
color.hsl // => string: color in the HSL format
color.R // => number: red value of the color
color.G // => number: green value of the color
color.B // => number: blue value of the color
color.values // => number[]: array of the RGB values (eg. [255, 165, 0])
color.luminance // => number: the color's luminance

Instance methods

Set a new value

#set(color: anyColor): Color

Sets a new color value of the color, returning a new, modified color. This method doesn't actually modify the color it's invoked on. This method follows the same rules as the "Creation" section, except id doesn't support an empty call, meaning the desired color have to be provided.

Parameters

color - Color or a Color object to set.

Returns

A new Color object with the color being the one provided.

Examples

const black = Color.create('#000000')
const white = black.set('#FFFFFF')
black !== white // => true

Calculate contrast with another color

#calculateContrastTo(color: anyColor): number

Calculates the contrast of the color compared to another one.

Parameters

color - Color or a Color object to which te comparison will be made.

Returns

A contract value.

Examples

const black = Color.create('#000000')
const white = Color.create('#FFFFFF')
blac.calculateContrastTo(white) // => 21

Check the color equality with another one

#equals(color: anyColor): boolean

Tests if the color object is of the same color as the tested one.

Parameters

color - Color or a Color object to test.

Returns

The test outcome as a boolean. true means it's the same color.

Examples

const black = Color.create('#000000')
const white = Color.create('#FFFFFF')
black.equals(white) // => false
black.equals(new Color('#000000')) // => true
black.equals('#000000') // => true

Use the color in a string context

#color.toString(): hexColor

Color object can be used in all places the string is expected. When concatenated with a string (or used in a template string), it's automatically transformed into it's hex representation. In other cases, the #toString() method transforms the object into hex.

Returns

A hex representation of the Color object.

Examples

const orange = Color.create('#FFA500')
"Color: " + orange // => "Color: #FFA500"
`I'm an orange with a value ${orange}` // => "I'm an orange with a value #FFA500"
color.toString() // => "#FFA500"

Colors types

Since all color are essentaily strings, the library aliases them for more explicit typing. Those types are exported for consumers to use them together with the library or as a standalone definitions.

Basic types

There are three basic color types:

• hexColor used for colors in the HEX format,
• rgbColor used for colors in the RGB format,
• hexColor used for colors in the HSL format.

There's also a basicColor type representing all three possible types.

To use them, just import required definitions from the @kolory/color-utilities module.

Examples

import {basicColor, hexColor, rgbColor, hslColor} from '@kolory/color-utilities'

const red: hexColor = '#FF0000'
const green: rgbColor = 'rgb(0, 255, 0)'
const blue: hslColor = 'hsl(240, 100%, 50%)'

let cameleon: basicColor
cameleon = '#FF0000'
cameleon = rgb(0, 255, 0)'
cameleon = 'hsl(240, 100%, 50%)'

Value types

In the internal calculations and raw colors management the library uses three value types representing values colors are consisted of.

• hexValue is used for a single value of the hex color (eg. A5 in #FFA500),
• hexColorValues is a triplet of hexValues and represents all three values of a hex color (eg. ['FF', 'A5', '00'] in #FFA500),
• colorValues is a triplet of the color's RGB values (eg. [255, 165, 0] in #FFA500).

Examples

import {colorValues, hexColorValues} from '@kolory/color-utilities'

const rawValuesOfOrange: colorValues = new ColorUtilities().parseColor('#FFA500')
const hexValuesOfOrange: hexColorValues = new ColorUtilities().splitHexColor('#FFA500')

Any color

When using the Color Object class that is not included in any of the basic colors, the anyColor type comes in handy. It's a union type of a basicColor type ane the type of the Color class.

Examples

import {anyColor} from '@kolory/color-utilities'

let rainbow: anyColor
rainbow = '#FF0000'
rainbow = rgb(0, 255, 0)'
rainbow = 'hsl(240, 100%, 50%)'
rainbow = Color.create('#FFA500')

License

MIT