a11y-contrast
rainbow
| a11y-contrast | rainbow | |
|---|---|---|
| 1 | 1 | |
| 31 | 1 | |
| - | - | |
| 5.9 | 3.2 | |
| 3 months ago | almost 3 years ago | |
| JavaScript | JavaScript | |
| MIT License | BSD 3-clause "New" or "Revised" License |
Stars - the number of stars that a project has on GitHub. Growth - month over month growth in stars.
Activity is a relative number indicating how actively a project is being developed. Recent commits have higher weight than older ones.
For example, an activity of 9.0 indicates that a project is amongst the top 10% of the most actively developed projects that we are tracking.
a11y-contrast
-
USWDS: The United States Web Design System
> Especially the contrast/magic number discussion.
From a developer perspective, working with color palettes with defined "magic numbers" is really great. I have written a blog post [1] around this topic and wrote a tool [2] to calculate/ensure accessible magic numbers for color palettes.
[1] https://darekkay.com/blog/accessible-color-palette/
[2] https://github.com/darekkay/a11y-contrast
rainbow
-
Accessible Text on Images: Nail the Contrast Ratio
The Rainbow tool was built using a static site generator. It's power lies in a Rust serverless function which does the maths. It works by finding the pixel (in the image) with the lowest contrast to the text colour. Then it uses a bit of High School Maths (the Newton-Raphson numerical technique) to work out the overlay transparency which satisfies the contrast ratio supplied (4.5 by default). There are a few optimisations built in such as resizing the image before getting going to speed up the later calculations. The code is open source and you can view the Rainbow Site code on the Rodney Lab Git Hub page. Now you know what the Rainbow tool is shall we look at how to use it?
What are some alternatives?
random-colors-palette
leonardo - Generate colors based on a desired contrast ratio
testimonial - Jamstack app using Gatsby, Netlify, and FaunaDB.
gifa11y - Gifa11y is a customizable vanilla javascript plugin that easily adds accessible play/pause buttons to animated GIFs.
next-on-netlify - Build and deploy Next.js applications with Server-Side Rendering on Netlify!
apca-w3 - The APCA version, to be licensed for use with guidelines: W3/AGWG.
Alt-Text-Generator - Generate alt text for your images!
bootstrap-vue - BootstrapVue provides one of the most comprehensive implementations of Bootstrap v4 for Vue.js. With extensive and automated WAI-ARIA accessibility markup.