colorizr

v4.0.1

Published

2 months ago

Manipulate colors like a boss

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gilbarbara

color color manipulation wcag a11y

Colorizr

A modern color library focused on perceptual correctness and accessibility.

Highlights

🏖 Easy to use: Works with Hex, HSL, RGB, OKLAB, and OKLCH.
♿️ Accessibility: WCAG 2.x contrast and APCA (WCAG 3.0) support.
🎨 Design Systems: Generate perceptual color scales with variants.
🖥 Modern Displays: P3 gamut optimization and OkLCH operations.
🟦 TypeScript: Full type safety, zero dependencies.

Setup

Install

npm i colorizr

Usage

You can use the functions standalone or compose them freely:

import { scale, readableColor } from 'colorizr';

const swatches = scale('#ff0044');

const accessibleSwatches = Object.entries(swatches).map(
  ([key, color]) => ({
    key,
    color,
    text: readableColor(color),
  }),
);

Or you can create an instance to use all the methods for the same color:

import Colorizr from 'colorizr';

const colorInstance = new Colorizr('#ff0044');
colorInstance.luminance; // 0.2168
colorInstance.chroma; // 1
colorInstance.opacity; // 1

API

String inputs accept css values: hex, hsl, oklab, oklch, rgb, and named colors.

Info – basic color properties and metadata
Manipulators – adjust lightness, saturation, hue, alpha
Converters – between color spaces
Generators – palettes, schemes, scales
Comparison – WCAG & APCA
Utilities – helpers for parsing, formatting, random colors
Validators – type and format validation
Class – object-oriented API for a single color

Info

chroma(input: string): number
Get the chroma of a color.

import { chroma } from 'colorizr';

chroma('#ff0044'); // 1
chroma('#ffc0cb'); // 0.2471

luminance(input: string): number
Get the relative brightness according to the WCAG definition.
Normalized to 0 for black and 1 for white.

import { luminance } from 'colorizr';

luminance('#ff0044'); // 0.2168

name(input: string): string
Get the name of a color. Return the hex code if it can't be named.

import { name } from 'colorizr';

name('#ffc0cb'); // pink
name('rgb(176 224 230)'); // 'powderblue'
name('hsl(344 100 50)'); // #ff0044

opacity(input: string): number
Get the opacity of a color.

import { opacity } from 'colorizr';

opacity('#ff0044'); // 1
opacity('rgb(255 0 68 / 90%)'); // 0.9
opacity('hsl(344 100 50 / 60%)'); // 0.6

Manipulators

lighten(input: string, amount: number): string
Get a color with increased lightness.

import { lighten } from 'colorizr';

lighten('#ff0044', 10); // #ff3369
lighten('hsl(136 100% 50%)', 10); // hsl(136 100% 60%)

darken(input: string, amount: number): string
Get a color with decreased lightness.

import { darken } from 'colorizr';

darken('#ff0044', 10); // #cc0036
darken('oklch(47.642% 0.29956 274.93693)', 10); // oklch(40.377% 0.25281 275.46794)

saturate(input: string, amount: number): string
Get a color with increased saturation.

import { saturate } from 'colorizr';

saturate('#ff0044', 10); // #ff0044 (already at the maximum)
saturate('pink', 10); // #ffc0cb

desaturate(input: string, amount: number): string
Get a color with decreased saturation.

import { desaturate } from 'colorizr';

desaturate('#ff0044', 10); // #f20d4a
desaturate('oklab(70.622% 0.1374 0.14283)', 10); // oklab(69.021% 0.12176 0.13721)

invert(input: string): string
Invert the color by rotating the hue 180 degrees.

import { invert } from 'colorizr';

invert('#07e'); // '#ee7700'
invert('#f058'); // '#00ffaa'

rotate(input: string, degrees: number): string
Get a color with a hue rotated by the specified degrees.

import { rotate } from 'colorizr';

rotate('#ff0044', 30); // #ff3b00

opacify(input: string, alpha: number, format?: ColorType): string
Add opacity to a color

import { opacify } from 'colorizr';

opacify('hsl(344 100% 50%)', 0.9); // hsl(344 100% 50% / 90%)
opacify('#ff0044', 0.8); // #ff0044cc

transparentize(input: string, alpha: number, format?: ColorType): string
Increase/decrease the color opacity. The alpha range is -1 to 1 (positive decreases opacity, negative increases it).

import { transparentize } from 'colorizr';

transparentize('hsl(344 100% 50%)', 0.1); // hsl(344 100% 50% / 90%)
transparentize('#ff0044', 0.5); // #ff004480
transparentize('#ff004480', -0.2); // #ff0044b3 (increases opacity)

grayscale(input: string, format?: ColorType): string
Convert a color to grayscale using OkLCH (perceptually uniform).

import { grayscale } from 'colorizr';

grayscale('#ff0044'); // '#8a8a8a'
grayscale('hsl(180, 50%, 50%)'); // 'hsl(0 0% 66.67%)'
grayscale('#ff0000', 'oklch'); // 'oklch(62.796% 0 29.23494)'

mix(color1: string, color2: string, ratio?: number, format?: ColorType): string
Mix two colors in OkLCH space with shortest-path hue interpolation.

import { mix } from 'colorizr';

mix('#ff0000', '#0000ff'); // '#ba00c2' (50% mix)
mix('#ff0000', '#0000ff', 0.25); // '#e8007b'
mix('#000000', '#ffffff', 0.5); // '#636363'
mix('hsl(0, 100%, 50%)', '#0000ff', 0.5); // 'hsl(297.53 100% 38.04%)'

Comparison

brightnessDifference(left: string, right: string): number
Get the brightness difference between the two colors.

import { brightnessDifference } from 'colorizr';

brightnessDifference('#fff', 'rgb(255, 0, 68)'); // 171.003

colorDifference(left: string, right: string): number
Get the color difference between the two colors.

import { colorDifference } from 'colorizr';

colorDifference('hsl(0 0% 100%)', '#f04'); // 442

compare(left: string, right: string): Analysis
Get the WCAG analysis between two colors.

import { compare } from 'colorizr';

compare('#ff0044', '#fff');

({
  "brightnessDifference": 171.003,
  "colorDifference": 442,
  "compliant": 1,
  "contrast": 3.94,
  "largeAA": true,
  "largeAAA": false,
  "normalAA": false,
  "normalAAA": false,
})

contrast(left: string, right: string): number
Get the WCAG contrast ratio between two colors.

import { contrast } from 'colorizr';

contrast('hsl(0 0% 100%)', 'rgb(255 0 68)'); // 3.94

Generators

palette(input: string, options?: PaletteOptions): string[]
Generate a palette of colors.

interface PaletteOptions {
  /**
   * Output color format.
   *
   * If not specified, the output will use the same format as the input color.
   */
  format?: ColorType;
  /**
   * Adjusts the lightness of the base color before generating the palette.
   *
   * Value should be between 0 and 100.
   */
  lightness?: number;
  /**
   * Adjusts the saturation of the base color before generating the palette.
   *
   * Value should be between 0 and 100.
   */
  saturation?: number;
  /**
   * The number of colors to generate in the palette.
   *
   * Minimum value is 2.
   * @default 6
   */
  size?: number;
  /**
   * Generate a monochromatic palette.
   *
   * For more options, use the `scale` function.
   */
  type?: 'monochromatic';
}

import { palette } from 'colorizr';

palette('#ff0044');
// ['#ff0044', '#ff7700', '#88ff00', '#00ff77', '#0088ff', '#7700ff'];

palette('#ff0044', { type: 'monochromatic' });
// ['#ff99b4', '#ff5582', '#ff1150', '#cc0036', '#880024', '#440012']

scheme(input: string, type: SchemeOptions): string[]
Get a color scheme.

interface SchemeOptions {
  /**
   * Output color format.
   *
   * If not specified, the output will use the same format as the input color.
   */
  format?: ColorType;
  /**
   * The type of scheme to generate.
   * @default 'complementary'
   */
  type?: Scheme;
}

import { scheme } from 'colorizr';

const complementary = scheme('rgb(255 0 68)'); // ['rgb(255 0 68)', 'rgb(0 255 187)']
const triadic = scheme('#ff0044', 'triadic'); // ['#ff0044', '#44ff00', '#0044ff']

scale(input: string, options?: ScaleOptions): Record<number, string>
Generate a perceptual color scale with advanced options.

interface ScaleOptions {
  /**
   * Controls chroma adjustment across lightness levels.
   * Values between 0-1 interpolate between these behaviors.
   *
   * @default 0
   */
  chromaCurve?: number;
  /**
   * Output color format.
   *
   * Determines the format of the generated colors (e.g., HEX, RGB, OKLCH, etc.).
   *
   * If not specified, the output will match the format of the input color.
   */
  format?: ColorType;
  /**
   * The lightness tuning factor for the scale.
   * - 1: Linear lightness distribution.
   * - >1: Lighter tones are emphasized.
   * - <1: Darker tones are emphasized.
   * @default 1.5
   */
  lightnessCurve?: number;
  /**
   * Lock input color at specific step position.
   *
   * The input color will appear exactly at this step, and other steps
   * will be calculated relative to this anchor point.
   *
   * Must be a valid key for the current step count.
   */
  lock?: number;
  /**
   * The maximum lightness value for the scale.
   *
   * Defines the upper bound for the lightest color in the palette.
   *
   * A number between 0 and 1.
   * @default 0.97
   */
  maxLightness?: number;
  /**
   * The minimum lightness value for the scale.
   *
   * Defines the lower bound for the darkest color in the palette.
   *
   * A number between 0 and 1.
   *
   * @default 0.2
   */
  minLightness?: number;
  /**
   * Theme-aware lightness direction.
   *
   * - 'light': Low keys (50) are lightest, high keys (950) are darkest
   * - 'dark': Low keys (50) are darkest, high keys (950) are lightest
   *
   * @default 'light'
   */
  mode?: ScaleMode;
  /**
   * Global saturation override (0-100).
   *
   * When set, overrides the chroma for all generated shades.
   * Maps to chroma in OKLCH space.
   *
   * Overrides `variant` if both are set.
   */
  saturation?: number;
  /**
   * Number of steps in the scale (3-20).
   *
   * Controls how many color shades are generated.
   *
   * @default 11
   */
  steps?: number;
  /**
   * The variant of the scale.
   * - 'deep': Generates rich and bold tones with significantly reduced lightness.
   * - 'neutral': Generates muted tones by reducing chroma.
   * - 'pastel': Produces soft and airy tones with significant chroma reduction.
   * - 'subtle': Creates extremely desaturated tones, close to grayscale.
   * - 'vibrant': Enhances chroma for bold and striking tones.
   */
  variant?: ScaleVariant;
}

import { scale } from 'colorizr';

scale('#ff0044');
/*
{
  50: '#ffeeed',
  100: '#ffe0df',
  200: '#ffc7c6',
  300: '#ffa7a7',
  400: '#ff8186',
  500: '#ff5464',
  600: '#f20f42',
  700: '#d40021',
  800: '#ad0000',
  900: '#7d0000',
  950: '#470000'
}
*/

scale(
  '#ff0044',
  { lightnessCurve: 1.6, lock: 500, steps: 10, format: 'oklch' },
);
/*
{
  50: 'oklch(97% 0.25404 19.90218)',
  100: 'oklch(94.432% 0.25404 19.90218)',
  200: 'oklch(89.214% 0.25404 19.90218)',
  300: 'oklch(82.104% 0.25404 19.90218)',
  400: 'oklch(73.397% 0.25404 19.90218)',
  500: 'oklch(63.269% 0.25404 19.90218)',
  600: 'oklch(58.561% 0.25404 19.90218)',
  700: 'oklch(48.996% 0.25404 19.90218)',
  800: 'oklch(35.962% 0.25404 19.90218)',
  900: 'oklch(20% 0.25404 19.90218)'
}
*/

getScaleStepKeys(steps: number): number[]
Get the step keys for a given step count (3-20).

import { getScaleStepKeys } from 'colorizr';

getScaleStepKeys(3);  // [100, 500, 900]
getScaleStepKeys(5);  // [100, 300, 500, 700, 900]
getScaleStepKeys(11); // [50, 100, 200, 300, 400, 500, 600, 700, 800, 900, 950]

Converters

The default precision is 5.

convert(input: string, format: ColorType): string
Convert a color string to another format.

import { convert } from 'colorizr';

convert('#ff0044', 'hsl') // hsl(344 100% 50%)
convert('rgb(255 0 68)', 'oklch') // oklch(63.269% 0.25404 19.90218)

hex2hsl(input: string): HSL
Convert HEX to HSL.

import { hex2hsl } from 'colorizr';

hex2hsl('#ff0044'); // { h: 344, s: 100, l: 50 }

hex2oklab(input: string, precision?: number): LAB
Convert HEX to OKLAB.

import { hex2oklab } from 'colorizr';

hex2oklab('#ff0044'); // { l: 0.63269, a: 0.23887, b: 0.08648 }

hex2oklch(input: string, precision?: number): LCH
Convert HEX to OKLCH.

import { hex2oklch } from 'colorizr';

hex2oklch('#ff0044'); // { l: 0.63269, c: 0.25404, h: 19.90218 }

hex2rgb(input: string): RGB
Convert HEX to RGB.

import { hex2rgb } from 'colorizr';

hex2rgb('#ff0044'); // { r: 255, g: 0, b: 68 }

hsl2hex(input: HSL | ColorTuple): string
Convert HSL to HEX.

import { hsl2hex } from 'colorizr';

hsl2hex({ h: 344, s: 100, l: 50 }); // '#ff0044'
hsl2hex([344, 100, 50]); // '#ff0044'

hsl2oklab(input: HSL | ColorTuple, precision?: number): LAB
Convert HSL to OKLAB.

import { hsl2oklab } from 'colorizr';

hsl2oklab({ h: 344, s: 100, l: 50 }); // { l: 0.63269, a: 0.23887, b: 0.08648 }
hsl2oklab([344, 100, 50]); // { l: 0.63269, a: 0.23887, b: 0.08648 }

hsl2oklch(input: HSL | ColorTuple, precision?: number): LCH
Convert HSL to OKLCH.

import { hsl2oklch } from 'colorizr';

hsl2oklch({ h: 344, s: 100, l: 50 }); // { l: 0.63269, c: 0.25404, h: 19.90218 }
hsl2oklch([344, 100, 50]); // { l: 0.63269, c: 0.25404, h: 19.90218 }

hsl2rgb(input: HSL | ColorTuple): RGB
Convert HSL to RGB.

import { hsl2rgb } from 'colorizr';

hsl2rgb({ h: 344, s: 100, l: 50 }); // { r: 255, g: 0, b: 68 }
hsl2rgb([344, 100, 50]); // { r: 255, g: 0, b: 68 }

oklab2hex(input: LAB | ColorTuple): string
Convert OKLAB to HEX.

import { oklab2hex } from 'colorizr';

oklab2hex({ l: 0.63269, a: 0.23887, b: 0.08648 }); // '#ff0044'
oklab2hex([0.63269, 0.23887, 0.08648]); // '#ff0044'

oklab2hsl(input: LAB | ColorTuple): HSL
Convert OKLAB to HSL.

import { oklab2hsl } from 'colorizr';

oklab2hsl({ l: 0.63269, a: 0.23887, b: 0.08648 }); // { h: 344, s: 100, l: 50 }
oklab2hsl([0.63269, 0.23887, 0.08648]); // { h: 344, s: 100, l: 50 }

oklab2oklch(input: LAB | ColorTuple, precision?: number): LCH
Convert OKLAB to OKLCH.

import { oklab2oklch } from 'colorizr';

oklab2oklch({ l: 0.63269, a: 0.23887, b: 0.08648 }); // { l: 0.63269, c: 0.25404, h: 19.90218 }
oklab2oklch([0.63269, 0.23887, 0.08648]); // { l: 0.63269, c: 0.25404, h: 19.90218 }

oklab2rgb(input: LAB | ColorTuple, precision: number = 0): RGB
Convert OKLAB to RGB.

import { oklab2rgb } from 'colorizr';

oklab2rgb({ l: 0.63269, a: 0.23887, b: 0.08648 }); // { r: 255, g: 0, b: 68 }
oklab2rgb([0.63269, 0.23887, 0.08648]); // { r: 255, g: 0, b: 68 }

oklch2hex(input: LCH | ColorTuple): string
Convert OKLCH to HEX.

import { oklch2hex } from 'colorizr';

oklch2hex({ l: 0.63269, c: 0.25404, h: 19.90218 }); // '#ff0044'
oklch2hex([0.63269, 0.25404, 19.90218]); // '#ff0044'

oklch2hsl(input: LCH | ColorTuple): HSL
Convert OKLCH to HSL.

import { oklch2hsl } from 'colorizr';

oklch2hsl({ l: 0.63269, c: 0.25404, h: 19.90218 }); // { h: 344, s: 100, l: 50 }
oklch2hsl([0.63269, 0.25404, 19.90218]); // { h: 344, s: 100, l: 50 }

oklch2oklab(input: LCH | ColorTuple, precision?: number): LAB
Convert OKLCH to OKLAB.

import { oklch2oklab } from 'colorizr';

oklch2oklab({ l: 0.63269, c: 0.25404, h: 19.90218 }); // { l: 0.63269, a: 0.23887, b: 0.08648 }
oklch2oklab([0.63269, 0.25404, 19.90218]); // { l: 0.63269, a: 0.23887, b: 0.08648 }

oklch2rgb(input: LCH | ColorTuple, precision: number = 0): RGB
Convert OKLCH to RGB.

import { oklch2rgb } from 'colorizr';

oklch2rgb({ l: 0.63269, c: 0.25404, h: 19.90218 }); // { r: 255, g: 0, b: 68 }
oklch2rgb([0.63269, 0.25404, 19.90218]); // { r: 255, g: 0, b: 68 }

rgb2hex(input: RGB | ColorTuple): string
Convert RGB to HEX.

import { rgb2hex } from 'colorizr';

rgb2hex({ r: 255, g: 0, b: 68 }); // '#ff0044'
rgb2hex([255, 0, 68]); // '#ff0044'

rgb2hsl(input: RGB | ColorTuple): HSL
Convert RGB to HSL.

import { rgb2hsl } from 'colorizr';

rgb2hsl({ r: 255, g: 0, b: 68 }); // { h: 344, s: 100, l: 50 }
rgb2hsl([255, 0, 68]); // { h: 344, s: 100, l: 50 }

rgb2oklab(input: RGB | ColorTuple, precision?: number): LAB
Convert RGB to OKLAB.

import { rgb2oklab } from 'colorizr';

rgb2oklab({ r: 255, g: 0, b: 68 }); // { l: 0.63269, a: 0.23887, b: 0.08648 }
rgb2oklab([255, 0, 68]); // { l: 0.63269, a: 0.23887, b: 0.08648 }

rgb2oklch(input: RGB | ColorTuple, precision?: number): LCH
Convert RGB to OKLCH.

import { rgb2oklch } from 'colorizr';

rgb2oklch({ r: 255, g: 0, b: 68 }); // { l: 0.63269, c: 0.25404, h: 19.90218 }
rgb2oklch([255, 0, 68]); // { l: 0.63269, c: 0.25404, h: 19.90218 }

Utilities

addAlphaToHex(input: string, alpha: number): string
Add an alpha value to a hex string

import { addAlphaToHex } from 'colorizr';

addAlphaToHex('#ff0044', 0.9); // '#ff0044e6'
addAlphaToHex('#ff0044cc', 0.9); // '#ff0044e6'

apcaContrast(background: string, foreground: string): number
Calculate APCA contrast between two colors. APCA (Accessible Perceptual Contrast Algorithm) is the contrast method proposed for WCAG 3.0.

Returns the Lc (Lightness contrast) value:

Positive values indicate dark text on light background
Negative values indicate light text on dark background

import { apcaContrast } from 'colorizr';

apcaContrast('#ffffff', '#000000'); // 106.04 (black text on white bg)
apcaContrast('#000000', '#ffffff'); // -107.88 (white text on black bg)
apcaContrast('#888888', '#ffffff'); // -68.54 (white text on gray bg)

convertAlphaToHex(input: number): string
Convert an alpha value to a hex value.

import { convertAlphaToHex } from 'colorizr';

convertAlphaToHex(0.5); // '80'

extractAlphaFromHex(input: string): number
Extract the alpha value from a hex string

import { extractAlphaFromHex } from 'colorizr';

extractAlphaFromHex('#ff004480'); // 0.5

extractColorParts(input: string): ExtractColorPartsReturn
Extract the color parts from a CSS color string. Hex colors are not supported.

type ExtractColorPartsReturn = {
  alpha?: number;
  model: 'hsl' | 'oklab' | 'oklch' | 'rgb';
} & Record<string, number>;

extractColorParts('rgb(255 0 68)') // { model: 'rgb', r: 255, g: 0, b: 68 }
extractColorParts('hsl(344 100% 50% / 90%)') // { alpha: 0.9, model: 'hsl', h: 344, s: 100, l: 50 }

formatCSS(input: HSL | RGB, options?: FormatCSSOptions): string
Get a CSS string from a color object.

interface FormatCSSOptions {
  /**
   * The alpha value of the color (0-1).
   */
  alpha?: number;
  /**
   * Output color format.
   * @default 'hex'
   */
  format?: ColorType;
  /**
   * The number of digits of the output.
   * @default 5
   */
  precision?: number;
  /**
   * The separator between the values.
   *
   * oklab and oklch always use space as a separator.
   * @default ' '
   */
  separator?: string;
}

import { formatCSS } from 'colorizr';

formatCSS({ h: 344, s: 100, l: 50 }, { format: 'rgb' }); // 'rgb(255, 0, 68)'
formatCSS({ r: 255, g: 0, b: 68 }, { alpha: 0.5, format: 'hsl' }); // 'hsla(344, 100%, 50%, 0.5)'

formatHex(input: string): string
Format a short hex string of 3 (or 4) digits into 6 (or 8) digits.

import { formatHex } from 'colorizr';

formatHex('#07e'); // '#0077ee'
formatHex('#f058'); // '#ff005588'

getColorType(input: string): ColorTypeInput | null
Detect the color type from a CSS color string.

import { getColorType } from 'colorizr';

getColorType('#ff0044'); // 'hex'
getColorType('red'); // 'named'
getColorType('hsl(344 100% 50%)'); // 'hsl'
getColorType('rgb(255 0 68)'); // 'rgb'
getColorType('oklab(0.63 0.24 0.09)'); // 'oklab'
getColorType('oklch(0.63 0.25 20)'); // 'oklch'
getColorType('invalid'); // null

getOkLCHMaxChroma(input: string | LCH, precision?: number): number
Get the maximum chroma for a given lightness and hue in the OkLCH color space.

import { getOkLCHMaxChroma } from 'colorizr';

getOkLCHMaxChroma({ l: 0.63269, c: 0.25404, h: 19.90218 }); // 0.28643
getOkLCHMaxChroma('#00ff44'); // 0.30921

getP3MaxColor(input: string | LCH): string
Get a OkLCH color with maxed chroma in the P3 color space.

import { getP3MaxColor } from 'colorizr';

getP3MaxColor({ l: 0.63269, c: 0.25404, h: 19.90218 }); // oklch(0.63269 0.28643 19.90218)
getP3MaxColor('#00ff44'); // oklch(0.86876 0.30921 144.65534)

parseCSS(input: string, format?: ColorType): string | HSL | RGB
Parse a css string to hex, HSL, OKLAB, OKLCH, or RGB.
If the format isn't set, it will return the same format as the input.

import { parseCSS } from 'colorizr';

parseCSS('hsl(344 100% 50%)'); // { h: 344, l: 50, s: 100 }
parseCSS('#ff0044', 'hsl'); // { h: 344, l: 50, s: 100 }

random(options?: RandomOptions): string
Generate a random color.

interface RandomOptions {
  /**
   * The color format to return.
   * @default 'hex'
   */
  format?: ColorType;
  /**
   * Maximum hue value (0-360).
   * @default 360
   */
  maxHue?: number;
  /**
   * Maximum lightness value (0-100).
   * @default 90
   */
  maxLightness?: number;
  /**
   * Maximum saturation value (0-100).
   * @default 100
   */
  maxSaturation?: number;
  /**
   * Minimum hue value (0-360).
   * If minHue > maxHue, the range wraps around 0° (e.g., 330-30 for reds).
   * @default 0
   */
  minHue?: number;
  /**
   * Minimum lightness value (0-100).
   * @default 10
   */
  minLightness?: number;
  /**
   * Minimum saturation value (0-100).
   * @default 10
   */
  minSaturation?: number;
}

import { random } from 'colorizr';

random(); // '#b385e0'
random({ format: 'oklch', minLightness: 40 }) // oklch(58.443% 0.2934 306.42895)

removeAlphaFromHex(input: string): string
Remove the alpha value from a hex string

import { removeAlphaFromHex } from 'colorizr';

removeAlphaFromHex('#ff0044cc'); // '#ff0044'

readableColor(backgroundColor: string, options?: ReadableColorOptions): string
Get the most readable color (light or dark) for a given background.

interface ReadableColorOptions {
  /**
   * The dark color to return if the background is light.
   * @default '#000000'
   */
  darkColor?: string;
  /**
   * The light color to return if the background is dark.
   * @default '#ffffff'
   */
  lightColor?: string;
  /**
   * The method to use for determining contrast.
   *
   * - `yiq`: YIQ brightness formula (fast, simple)
   * - `wcag`: WCAG 2.x relative luminance threshold
   * - `contrast`: WCAG 2.x contrast ratio comparison
   * - `oklab`: OkLab perceptual lightness threshold
   * - `apca`: APCA contrast comparison (WCAG 3.0 candidate)
   *
   * @default 'yiq'
   */
  method?: ReadableColorMethod;
  /**
   * The threshold for threshold-based methods.
   *
   * - `yiq`: 0-255 (default: 128)
   * - `wcag`: 0-1 (default: 0.5)
   * - `oklab`: 0-1 (default: 0.5)
   * - `contrast` and `apca`: ignored (comparison-based)
   */
  threshold?: number;
}

import { readableColor } from 'colorizr';

readableColor('#ff0044'); // '#ffffff' (using yiq)
readableColor('#fff800'); // '#000000'

// Using different methods
readableColor('#808080', { method: 'wcag' }); // '#ffffff'
readableColor('#808080', { method: 'contrast' }); // '#000000'
readableColor('#808080', { method: 'apca' }); // '#ffffff'

// Custom colors and threshold
readableColor('#ff0044', {
  darkColor: '#111',
  lightColor: '#eee',
  threshold: 150  // for yiq method (0-255)
});

readableColor('#ff0044', {
  method: 'wcag',
  threshold: 0.4  // for wcag/oklab methods (0-1)
});

readableColorAPCA(backgroundColor: string, options?: ReadableColorAPCAOptions): string
Get the most readable color using APCA contrast. Standalone function for APCA method.

interface ReadableColorAPCAOptions {
  /**
   * The dark color to return if it has better contrast.
   * @default '#000000'
   */
  darkColor?: string;
  /**
   * The light color to return if it has better contrast.
   * @default '#ffffff'
   */
  lightColor?: string;
}

import { readableColorAPCA } from 'colorizr';

readableColorAPCA('#ffffff'); // '#000000'
readableColorAPCA('#000000'); // '#ffffff'
readableColorAPCA('#888888'); // '#ffffff' (APCA favors light text on mid-grays)

Validators

isValidColor(input: string, type?: ColorTypeInput): boolean
Check if the input is a valid color. Optionally validate against a specific color type.

import { isValidColor } from 'colorizr';

isValidColor('#ff0044'); // true
isValidColor('#ff004400'); // true
isValidColor('hsl(136 100% 50%)'); // true
isValidColor('hsla(344, 100%, 50%, 0.4)'); // true
isValidColor('oklab(70.622% 0.1374 0.14283)'); // true
isValidColor('oklch(47.642% 0.29956 274.93693)'); // true
isValidColor('rgb(255 230 109)'); // true
isValidColor('blue'); // true
isValidColor('aliceblue'); // true
isValidColor('#mmff00'); // false
isValidColor('blue-ish'); // false

// With type validation
isValidColor('#ff0044', 'hex'); // true
isValidColor('#ff0044', 'hsl'); // false
isValidColor('hsl(0 100% 50%)', 'hsl'); // true
isValidColor('blue', 'named'); // true
isValidColor('blue', 'hex'); // false

isHex(input: unknown): boolean
Check if the input is a valid hex color.

import { isHex } from 'colorizr';

isHex('#f04'); // true
isHex('#ff0044'); // true
isHex('#ff0044cc'); // true

isHSL(input: unknown): boolean
Check if the input is a valid HSL object.

import { isHSL } from 'colorizr';

isHSL({ h: 344, s: 100, l: 50 }); // true

isLAB(input: unknown): boolean
Check if the input is a valid LAB color.

import { isLAB } from 'colorizr';

isLAB({ l: 0.63269, a: 0.23887, b: 0.08648 }); // true

isLCH(input: unknown): boolean
Check if the input is a valid LCH color.

import { isLCH } from 'colorizr';

isLCH({ l: 0.63269, c: 0.25404, h: 19.90218 }); // true

isRGB(input: unknown): boolean
Check if the input is a valid RGB color.

import { isRGB } from 'colorizr';

isRGB({ r: 255, g: 0, b: 68 }); // true

Class

import Colorizr from 'colorizr';

const colorizr = new Colorizr('#ff0044');

colorizr.hex; // #ff0044
colorizr.hsl; // { h: 344, s: 100, l: 50 };
colorizr.rgb; // { r: 255, g: 0, b: 68 };

Getters

colorizr.hex
Get the hex code.

colorizr.hsl
Get the HSL object.

colorizr.oklab
Get the OKLAB object.

colorizr.oklch
Get the OKLCH object.

colorizr.rgb
Get the RGB object.

colorizr.hue
Get the hue (0-360).

colorizr.saturation
Get the saturation (0-100).

colorizr.lightness
Get the lightness (0-100).

colorizr.red
Get the red level (0-255).

colorizr.green
Get the green level (0-255).

colorizr.blue
Get the blue level (0-255).

colorizr.chroma
Get the chroma (0-1).

colorizr.luminance
Get the luminance (0-1).

colorizr.opacity
Get the opacity (0-1).

colorizr.css
Get the css string of the same type as the input.

colorizr.readableColor
Get the most readable color (black or white) for this color as a background.

Methods

colorizr.format(type: ColorType, precision?: number)
Returns the formatted color in the specified format.

The class also includes all Manipulators (lighten, darken, saturate, desaturate, invert, rotate, opacify, transparentize, grayscale, mix) and Comparison methods (contrast, brightnessDifference, colorDifference, compare).

Credits / References

color.js
chroma-js
calculating-color-contrast
Colour Contrast Check
Converting Color Spaces in typescript
A perceptual color space for image processing
SAPC-APCA

License

MIT