WCAGColorContrast

A Ruby port of the Javascript https://github.com/doochik/wcag-color-contrast.

Calculates the contrast ratio between 2 colors, for checking against the WCAG recommended contrast ratio for legibility.

Installation

Add this line to your application's Gemfile:

gem 'wcag_color_contrast'

And then execute:

$ bundle

Or install it yourself as:

$ gem install wcag_color_contrast

Usage

With 2 hex colors as strings (3 or 6 characters, case insensitive, no leading pound/hash sign):

require 'wcag_color_contrast'
WCAGColorContrast.ratio('999', 'ffffff')
#=> 2.849027755287037

Can also calculate the relative luminance of a color

WCAGColorContrast.relative_luminance('008800')
#=> 0.17608318886144392

Contributing

1. Fork it
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create new Pull Request