contrast-color-generator

Javascript module for automatically generating well contrasted color with a color you specified.

Description

This module generating well contrasted color which satisfy W3C guideline. You can set minimum contrast ratio and source color as a parameter.

Demo

Install

You can install the module in your project.

$ npm install contrast-color-generator

Usage

in Node.js

This is an example is generating contrast color whose 'hue' is 180°

const { Generator } = require('contrast-color-generator');
let generator = new Generator(180);

let backgoundColor = '#800000';
let foregroundColor = generator.generate(inputColor).hexStr;

in a browser

in the case of loading from browser, this module define global variable 'contrastColor' This is an example is generating contrast color whose 'hue' is 180°.

<script src="contrast-color-generator.js"></script>
<script>
  let gen = new contrastColor.Generator(180);
  
  let backgoundColor = '#800000';
  let foregroundColor = gen.generate(inputColor).hexStr;
</script>

Principle

This module searches a color which has high contrast ratio against a input color from HSL color space. To calculate contrast ratios, it uses the definition of contrast ratio in W3C Guideline

In searching, H(specified by parameter) and S(of input color) are fixed, and it searches L which satisfies condition of contrast ratio using binary search.

By default, the first searching direction towards a brighter, And the second one towards darker. these behavior can be changed by a parameter.

Demo

This is the demo page of this module.

https://kenyog.github.io/contrast-color-generator/docs/example/index.html

Contribution

Welcome.

Licence

MIT

Author

kenyog