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Re: Auditing Without Sight

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From: Birkir R. Gunnarsson
Date: Aug 9, 2016 12:30PM

Hey all.

aXe is very accessible with a screen reader. I wrote a guide on it for
FireEyes II (which is the paid version), but can easily be updated for
the Firefox aXe plug-in (it is the same, minus a couple of features).
It is also very good at finding automated color contrast issues.

To launch the aXe Firefox plugin(once installed): go to tools ->
developer tools -> accessibility, and press enter.

Re calculating the ratio, once you have the color values you simply
plug them into a tool like the WebAIM color contrast checker:
http://webaim.org/resources/contrastchecker/

The tricky thing is when background images are used or if the
background color varies, it requires fairly in-depth assessment using
a pair of eyes, and taking the values at a couple of diffrrent points
on the element.
With color contrast there are often complications that make 100%
reliable automated testing, and testing, without sight not 100%
accurate.
We should still do it to the extent possible, we can catch a lot of
real issues, but for an official report I think we still need a pair
of eyes to verify, or at least spot check.

Jim, could you try to download Firebug and follow my instructions with
NVDA to see if the bringing NVDA up from the right click menu works
there.
If your workaround works, it shall instantly be added too the article.
Cheers
-Birkir


On 8/9/16, Swift, Daniel P. < <EMAIL REMOVED> > wrote:
> I actually looked into the math for the ratio (on a very superficial level).
> It's really not that simple because the ratio takes into consideration a
> variety of things. I don't remember the specifics, but it reminded me of
> how your ears respond to different frequencies at different volumes. In the
> end, I found it much easier to use the following site to check my contrast
> ratio:
>
> http://leaverou.github.io/contrast-ratio/#%23000-on-%23F00
>
> -Dan
>
>