W3C home > Mailing lists > Public > www-validator-css@w3.org > September 2007

Re: Validator - small bug

From: Jens Brueckmann <jens.brueckmann@gmail.com>
Date: Wed, 26 Sep 2007 16:43:33 +0200
Message-ID: <fe03a57b0709260743x1a525a8dw27ff162d7ffa0433@mail.gmail.com>
To: www-validator-css@w3.org
Cc: "Thomas Auge" <auge@virtues.net>

Hi Thomas,

> A real bug is the validator complaining about "body" and ".footer table"
> having the same background. ".footer" does have a background color
> defined, and unless I am missing something ".footer table" can only
> appear in the ".footer" context, which has the correct background. This
> might need fixing.

Actually, no.

Imagine a user Style sheet where all tables (or even all elements)
have background colour white set.

As user Style sheets have higher priority than author Style sheets,
your text would become unreadable.
Well, presumably a user who sets a background colour would also define
a text colour, then all would be well again.
But as you can never be sure about the user's settings, the validator
issues a warning (sic!), so that you become aware of possible issues.

> Another minor thing is that I am getting warnings about the same
> background and border color for some input fields. The border style is
> outset or inset for those, which causes the browser to actually lighten
> or darken the border color and the background color is often a good
> choice for that border type. The validator should probably check for
> border type "solid" before reporting these warnings.

The reason the validator warns (!) about similar background colours
and border colours is - as far as I understand it - that borders might
have been used to convey the "notion of 'separation'" [1].
If background and border have the same colour, this separation will
not be visible. If you use border styles such as 'inset', 'outset',
'ridge' or 'groove', the border will certainly become somewhat
visible. Nevertheless the colour contrast might be too low for some
people to recognize this.

All in all, these warnings are not errors. They are concerned with
probable accessibility issues.
If you are sure, your Style sheet does not pose any accessibility
issues, you may as well ignore these warnings (or even choose 'no
warnings' from the 'more options' select box).

[1] http://www.w3.org/TR/WCAG10-CSS-TECHS/#style-rules


Jens Brueckmann
Received on Wednesday, 26 September 2007 14:50:14 UTC

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