jessuni / SafeColor

Generate a consistent color from a string, or generate a random color from a given color. Both accessible, contrast safe, WCAG success criteria 1.4.3 compliant.

SafeColor

SafeColor generates accessible colors that comply with WCAG 2.1 success criteria 1.4.3 (or any contrast ratio of your choice). It can be used to:

1. generate a random color that is contrast safe with a given color
2. generate a consistent, contrast safe color for a string

No need to worry about your base color being light/dark or for foreground/background. If the given color is too light to meet your desired contrast ratio, SafeColor will look for a darker color and vise versa.

A lot of libraries can generate arbitrary colors. Why the fuss?

To improve web accessibility for people with color deficiencies, WCAG 2.1 requires that the visual presentation of text and images of text has a contrast ratio of at least 4.5:1(Level AA) or an enchanced contrast ratio of at least 7:1(Level AAA).

Complying with this principle will improve the accessibility of your web contents.

Install

npm install safecolor

Usage

import SafeColor from 'safecolor'

Basic

This will assume that the generated color should be contrast safe (>= Level AA: 4.5) with black(rgb(0, 0, 0))

  safeColor = new SafeColor()

  safeColor.random()
  // >> rgb(104, 145, 26)
  // contrast ratio = 5.65

  safeColor.random('hello world')
  // >> rgb(196,226,239)
  // contrast ratio = 15.47

With options

  safeColor = new SafeColor({
    color: [255, 255, 255],
    contrast: 4.5,
  })

  safeColor.random()
  // >> rgb(32,80,46)
  // contrast ratio = 9.34

  safeColor.random('hello world')
  // >> rgb(20,57,74)
  // contrast ratio = 12.25

Options

color

A base color. Should be 8bit RGB value in array [r, g, b]

• type: Array
• default: [0, 0, 0]

contrast

The minimum contrast ratio between the base color and the generated color.

• type: Number
• default: 4.5

Notice

ES6 features: destructing assignment and map are used in this script. You may need polyfills for the script to work properly.

Note: to keep this as simple as possible, the output is a RGB value in string. If any built-in conversions (to HEX, to HSL) will make SafeColor much more convenient for you, please contact me to add the feature or feel free to pull request. Cheers!