Color & Contrast (Desktop and Advanced Editor)

Using color is a great way to add interest and aesthetic value to a document.  It is, however, very important to be aware of how color is being used.  Depending on the standard(s) selected in the verification phase, multiple “User Verification” checkpoints may be triggered.    

In particular, pay attention to these two considerations:

1. If color is used as the only way to convey information then this needs to be fixed.  For example, in a data table, using the color red to indicate that some numbers are negative is not acceptable because people who are blind and people who are color blind to red will not be able to distinguish between positive and negative numbers.  A solution would be to place the negative numbers in a Span tag and give that Span the Actual text “negative” along with the number. 
2. Make sure that there is sufficient contrast between any background and foreground text/images so that people can easily see the content.  The best solution would be to return to the source document, fix the issue and regenerate the PDF.  Using the example in the previous scenario (negative numbers displayed in red), it is possible to put content in Span tags and provide appropriate Actual text so that assistive technology will present the information to someone who is listening to the document.  However, for contrast issues, this solution is ineffective, and as a result, the document remains out of compliance, because contrast issues may present problems for people who are significantly visually impaired.  (Manipulating the reading of content through the use of Span tags only helps people who are listening to the document, not people who are looking at it visually.)    

Additional Failures of the Color Checkpoint

There are other design techniques besides color that are often used incorrectly to convey information.  Assistive technology will not detect and announce the use of these techniques and, in addition, people who have limited vision may have a difficult time reading text formatted in the ways listed below.  For maximum accessibility, avoid conveying information solely through the use of:

• ALL CAPITAL LETTERS
• Bold 
• Italics
• Underlined
• Struck through (Struck through text can be particularly difficult to read for people who are visually impaired!)
• Inconsistent font

Note:  The above is not an “all-encompassing” list of problematic techniques.  The point is to make the remediator aware of these issues so that they can be fixed.

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