Infographics, Color, Signal, and Noise
When color is the sole container of information, it fails 1 out of 22 persons (and 1 out of 12 men)
And, I don’t think the WCAG AA, or AAA, nor Section 508 guidelines go far enough to provide the best possible experiences for persons with color-blindness.
Current Accessibility Guidelines
1.4.1-Level A-WCAG 2.0: Color is not used as the only visual means of conveying info.
Tags: forms,links,color and contrast, text alternatives (alt tags),UX design
Color should not be used as the only means of conveying information, because blind users are not able to see Colors, and Colorblind or older users may not see Colors correctly.
When using Color to convey information, use another means (like text) to convey the same information in another way
Do not rely solely on Color to identify links. Distinguish links from regular text by underlining them, bolding them, showing an icon next to each link, or some other means other than Color.
In forms, use not just Color but also text labels to identify required fields or fields with errors
How to test: Check manually.
302.3-Functional Support Criteria (Chapter 3)-Section 508:
If perception of color is required, at least one visual mode of operation that does not require color perception must be provided
In the bar chart below, blue, green, and red are used to differentiate the data bars, and there is a color key that identifies which colors are associated with which data types. However, when viewed by a color-blind person, the red and green bars can’t be differentiated. They both appear yellow. The bars lose their signal and become noise.
In a revised version of the bar chart, shown below the original, the data type labels are located directly adjacent to their associated bars. With this design, WCAG and 508 requirements can be met and accessibility achieved without altering any of the colors. However, if that design route were taken, a color-blind person would experience a higher cognitive load to sort-out the visual data due to a lack of color differentiation.
For that reason, the colors were also revised to provide cool/warm and light/dark differentiation between them in an effort to provide a similar experience to what a typical-color-sighted person would have. To maintain as much of the signal as possible.
That’s universal design.
To receive updates on the latest developments to the free I-See-U Blueprint for Inclusive, Socio-Emotional, Entertaining, and Universal design (external link)