W3C home > Mailing lists > Public > www-style@w3.org > August 2005

Re: Solving the alpha images and background-color problem

From: Laurens Holst <lholst@students.cs.uu.nl>
Date: Sat, 13 Aug 2005 12:19:08 +0200
Message-ID: <42FDC91C.5030805@students.cs.uu.nl>
To: Kelly Miller <lightsolphoenix@gmail.com>
CC: Emrah BASKAYA <emrahbaskaya@hesido.com>, "www-style.w3.org" <www-style@w3.org>

Kelly Miller wrote:
> I disagree with the syntax of this, but not the idea.  The problem is 
> "onimageload" suggests that this should be the color on ALL image 
> loading.  Remember that CSS3 also has a method of adding foreground 
> images in CSS, through the global 'content' property.  What you're 
> suggesting sounds like it should only work with background-image 
> (though it may be better to have it work with both; but this might be 
> difficult).
Good point. I’d say this notation generalises the problem by making it a 
property value that can potentially be applied to different values 
accepting colours as well. But if it only works for background images 
anyway, I don’t see the need for it, and why would we not just create a  
background-standin-color property then?

Also, I think it might be better to turn it around - not specify the 
‘onimageload’, but the ‘whileimagenotloaded’ (standin-color() sounds 
like a better name), if you understand what I mean. After all, if all 
goes right, the colour that is used after the image loads is the final 

Anyways, this was already somewhat an issue with transparent GIFs, but 
the advance of transparent PNGs makes this even more a much needed 
feature for many designs. So I hope that the CSS WG will consider this 
(and previous) proposal (or come up with a variant of their own).

> Also, while we're discussing accessibility, wouldn't it be useful for 
> CSS to have some kind of syntax that tells the browser if either the 
> background-color or text-color is user-overridden, the opposing colors 
> should be shifted to a 'negative' color?  As it is, changing text 
> color or background color on any site is dangerous because the user 
> may override one but not the other, leading to problems with 
> accessibility and readability.
It would be nice to have something like ‘user default background, but 
only if it contrasts sufficiently with foreground’, or ‘any of these 
foreground colours that contrasts most with the background colour’. 
Because currently it is not possible (or rather, very ill-advised) to 
set a foreground colour without also explicitly setting a background colour.

But that’s an entirely different subject :).


Ushiko-san! Kimi wa doushite, Ushiko-san!!
Laurens Holst, student, university of Utrecht, the Netherlands.
Website: www.grauw.nl. Backbase employee; www.backbase.com.
Received on Saturday, 13 August 2005 10:19:11 UTC

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