[Irl-dean] Color contrast and WCAG 2.2 priority?

[Barry McMullin]

On Wed, 17 Jan 2007, Gez Lemon wrote:

> For plain text in an image, a user can access the text alternate. For
> charts, diagrams, and other non-text content, the brief alternate
> might not be adequate, and the long description might disadvantage
> those who better understand visual representations than verbose
> descriptions. I have no idea if that was the thinking behind the
> checkpoint, but that is how I have always interpreted it.

Thanks Gez -

That's an interesting suggestion!

At first sight, it does seem like a bit of a stretch to me - but
that's just an immediate reaction.  There is nothing that I am
aware of, either in WCAG 1.0 or the supporting documents, that
explicitly suggests that the 2.2 prioritisation might depend on
how "complex" the image is.  On the other hand, there is no
explicit consideration of *any* role for text alternatives
in relation to 2.2, so it is all a bit murky/speculative.

It would seem like the set of people in the category of having a
significant color perception deficit but, despite that, generally
finding text substantially harder to perceive/interpret than
("high contrast") graphics, would be relatively small - which
would again tend to nudge this particular case toward priority 3
rather than 2.

Clearly, in the absence of any text alternative, WCAG 2.2 is
definitely priority 2; but I suppose, in the presence of
appropriate text alternatives (*even* long ones!), I would still
be fairly reluctant to say a site failed conformance at Double-A
*just* on the strength of poor contrast in images...

Best - Barry.