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RE: Colour blindness and accessibility

From: Christophe Strobbe <christophe.strobbe@esat.kuleuven.ac.be>
Date: Mon, 05 May 2003 17:15:37 +0200
Message-Id: <5.0.2.1.2.20030505163940.02a40e88@mailserv.esat.kuleuven.ac.be>
To: Nick Kew <nick@webthing.com>, w3c-wai-ig@w3.org

Hi Nick,

The user agents I was thinking of are current browsers such as Internet 
Explorer and Opera, where the user can define their own style sheet for all 
pages they visit. These may be 'limited', as you say, but they will be 
around for a long time, because many users never upgrade or switch 
browsers. If the user agent you had in mind exists, I'd like to hear about 
it. If it doesn't exist (or isn't being developed), then I don't see how 
your comment invalidates what I wrote. At the moment, I know of no way to 
override styles for mandatory fields other than the method that I described.

Regards,
Christophe Strobbe

At 20:15 30/04/2003, Nick Kew wrote:

>On Wed, 30 Apr 2003, Christophe Strobbe wrote:
>
> > >.mandatory      { color: red ; }
> > >
> > >and the colour-blind user has an instant override,
> >
> > This also demonstrates that using HTML and CSS can result in mixing up
> > structure and presentation (cf. Jukka Korpela's article on
> > http://www.cs.tut.fi/~jkorpela/styles/harmful.html). Because form elements
> > in HTML do not have an attribute called "mandatory" or "required", you
> > create a new type of field with class="mandatory" or class="required" or
> > whatever comes to mind. This means that the user has to check your HTML
> > code to find out which class selector they should at to their stylesheet.
> > So they would have to write
> > .mandatory, .required, .req { color: red;}
>
>You're postulating a user agent with very limited capabilities.
>
>The one I was postulating doesn't require anything so clumsy.  It
>will present you with an accessibility option that presents the
>classes defined in whatever stylesheet you happen to be viewing,
>and lets you apply presentational attributes on-the-fly.  So
>it'll list ".mandatory" as "color: red", and allow you to adjust
>it to "font-weight: bold", or whatever you want.  It could even
>directly highlight in a predefined way all elements having
>a given property.
>
>The basic point is that markup+style supports this kind of
>accessibility.  The limiting factor is user agents.
>
>--
>Nick Kew
Received on Monday, 5 May 2003 11:14:45 GMT

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