🎨 a11y-contrast-color 🎨

a11y-contrast-color is a utility library for calculating luminance, contrast ratio, and recommending appropriate contrast colors to ensure accessibility compliance in web applications.

It helps developers easily determine whether text and background color combinations meet the Web Content Accessibility Guidelines(WCAG) standards by providing functions to recommend contrast colors that can improve readability and accessibility.

Installation

npm install a11y-contrast-color

Or

yarn add a11y-contrast-color

Usage

getLuminance

Calculates the luminance of a color.

Parameters

• color: RGB (required): An array of three numbers representing the RGB values(value in the range of [0,255]) of the color.

Returns

• number: The calculated luminance value.

import { getLuminance } from 'a11y-contrast-color';

const luminance = getLuminance([255, 0, 0]);
console.log(luminance); // Output: 0.2126

getContrastRatio

Calculates the contrast ratio between two colors.

Parameters

• color1: RGB (required): The first color value in RGB format.
• color2: RGB (required): The second color value in RGB format.

Returns

• number: The contrast ratio between the two luminance values.

import { getContrastRatio } from 'a11y-contrast-color';

const color1 = [128, 128, 128];
const color2 = [255, 255, 255];
const contrastRatio = getContrastRatio(color1, color2);
console.log(contrastRatio); // Output: 3.949439...

getContrastColor

Determines the appropriate contrast color (black or white) for a given background color to ensure readability.

Parameters

• color: RGB (required): An array of three numbers representing the RGB values of the background color.
• luminance: number (required): The target luminance ratio to be achieved or exceeded.

Returns

• RGB | null: An array representing the RGB values of the contrast color, or null if no suitable color is found.

import { getContrastColor } from 'a11y-contrast-color';

const contrastColor = getContrastColor([255, 0, 0], 4.5);
console.log(contrastColor); // Output: [R, G, B] || null depending on the contrast requirement

All projects are under the MIT license. Please refer to the LICENSE file for more information.