APCA
APCA
⇦ HOME ⇧ UP ONECOLOR VISION LINKS
This is a curated collection of links relating to color vision and accessibility, with an emphasis on practical design advice and guidelines.
COMPREHENSIVE COLOR VISION & COLOR THEORY
Larry Arend’s
NASA’s Using Color in Information Display Graphics
Nate Baldwin’s
Color and Contrast
Bruce MacEvoy’s
Handprint site on Color Vision
Troy Sobotka’s
The Hitchhiker’s Guide to Digital Colour
COLOR & CONTRAST DESIGN TOOLS
APCA Text Contrast Calculator
- Official: apcacontrast.com technology demonstrator with dynamic text examples.
- Third Party APCA Tools a list of third party APCA based color & contrast tools.
Inclusive Reading Technologies Design Standards
- APCA Readability Criterion the current public draft guidelines for content authors and developers.
- Visual Readability Contrast Testing and conformance specifications
- Bronze Simple Mode Quickstart simplified specifications.
- Design Guide: Visual Contrast General design guidance.
Color Vision Deficiency (Colorblind) Simulator Web App
- myndex.com/CVD/ a web app based on Brettel, Viénot, & Mollon, with additional simulations, shows all at once for comparison.
Desktop Color Vision (Colorblind) Simulator
- colororacle.org A desktop app based on Brettel, Viénot, & Mollon
Interactive DataViz Color Palette Tool
- colorbrewer2.org a web app that allows exploring palettes as applied to a map.
AUTHORITATIVE PAPERS, ARTICLES, & BOOKS
The Realities And Myths Of Contrast And Color
by A.Somers
A plain language, in-depth primer to vision, color, and contrast for design, with an emphasis on typography and accessibility needs. Published by Smashing Magazine.
Designing Maps for Colorblind
by B.Jenny, N.Kelso
This paper covers in depth, issues of design for those with color vision deficiency.
Why APCA?
by A.Somers
This brief, plain language introduction into APCA, and how it solves the problems of WCAG_2 contrast.
Does the contrast ratio actually predict the legibility of website text?
by S. Waller
A comparison of WCAG 2 math and APCA, by Sam Waller, a PhD at the Engineering Design Centre, University of Cambridge, UK.
Please Stop Using Grey Text
by A.Somers
Debunking one of the worst myths regarding design contrast. This article went viral in early 2022.
Color Contrast Is Not As Black And White As It Seems
by Roger Attrill
A technical analysis of some of the problems with WCAG 2 contrast math, and comparing and analyzing APCA.
What’s Red & Black & Also Not Read?
by A.Somers
Do the WCAG 2 Contrast Guidelines help users with color vision issues? While this is a widely held belief, the truth may surprise you.
Orange You Accessible? A Mini Case Study on Color Ratio
by Ericka O’Connor
This article demonstrates how WCAG_2 is flawed for colorblind users, including studies conducted with individuals with color vision deficiency.
Better reading on the web
by A.Somers
Published by UX Collective. This article discusses and demonstrates the problems with WCAG 2 contrast math, methods, guidelines, and automated testing.
Guidelines for Using Color in Voting Systems
by Maureen Stone, Sharon J. Laskowski, Svetlana Z. Lowry
This book, available for free download from NIST, covers digital color design guide for the electronic displays of voting systems. It dives deeply into designing for color vision with a great deal of practical advice.
A Contrast of Errors
by A.Somers
A look into the history of the WCAG 2 contrast guidelines, some of the problems created by them, and a discussion of the proposed replacement, the APCA (Accessible Perceptual Contrast Algorithm).
Color Appearance Models
by Mark D. Fairchild
The essential resource for readers needing to understand visual perception and for those trying to produce, reproduce and measure color appearance in various applications such as imaging, entertainment, materials, design, architecture and lighting.
A Brief Overview of Color Vision Deficiency (Colorblind) with examples
CURATED COLOR LINK CATALOGS
Myndex Color and Contrast Resources.
Accessible Perceptual Contrast Algorithm Documentation Links