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Re: X11 Colors (was Last call comments on CSS3 module: color)

From: Chris Lilley <chris@w3.org>
Date: Wed, 29 May 2002 19:43:38 +0200
Message-ID: <1617010531.20020529194338@w3.org>
To: www-svg@w3.org, "Steven Pemberton" <steven.pemberton@cwi.nl>
CC: Tantek Çelik <tantek@cs.stanford.edu>, "fantasai" <fantasai@escape.com>, <www-style@w3.org>

On Wednesday, May 29, 2002, 5:15:25 PM, Steven wrote:

SP> Nice try, but that's not how it works either. I will agree that they are in
SP> SVG, but I cannot agree that means they are in CSS. It may mean that the SVG
SP> has requested they be added to CSS (have they?),

Not really. More that CSS has requested that SVG normatively reference
the CSS3 color module, and to do that, the stuff that we use for color
needs to be in there.

>> There appears to be consensus in www-style to deprecate the X11 colors.

SP> I don't see that. There were objections to adding X11 styles, and one
SP> suggestion was to add them and immediately deprecate them. Another
SP> suggestions was *not* to add them and deprecate them in SVG.

Reminding people that www-style is not the whole world - please also
ask the XSL people and the SVG people before suggesting deprecating
stuff that is shared between specifications.


>> Since this issue affects SVG, I think the consensus must include www-svg
SP> as
>> well, either way, hence I expanded the discussion to that forum.

Yes. Although all the actual developers are on the svg-dev list not
www-svg, but its a good idea to expand the audience.

SP> Possibly. They should at least be aware of the objections to the bad design
SP> of the X11 color set (newcomers, see the thread starting
SP> http://lists.w3.org/Archives/Public/www-style/2002May/0122.html)

Well there are objections to the bad design of HSL as well, of course.
I proposed a greatly superior solution, CNS, in 1996 [1] which was
perceptually even - changing lightness would change lightness
regardless of hue; changing hue would not alter lightness, the color
steps were evenly perceptually spaced, and scores very well in
scientifically conducted usability studies (much better than HSL for
example). None of these things is true of X11 or of HSL.

However, although most posters to www-style were in favour of it, it
never got to consensus, largely due to a poorly-informed critique by
David Perrell[2] who thought it was a subset of HSB (later retracted
[3] but mud sticks), the lack of online resources (it was fully
described, but in a print journal), and a general programmer aversion
to color theory, and general indifference to color reproducibility in
CSS implementors. It was just too high a bar, too early. Eventually I
stopped suggesting it. Instead we went for tying the RGB colors to a
real international standard for what they meant, rather than "device
RGB" and leaving it to authoring tools to provide color pickers,
lists, or whatever they wanted as a user interface.

In the end, if existing practice is interoperable (X11 colors, note
that even in 1996 [4] that thread had a referece to "Netscape/X11
named colors") or widely used in other areas (HSB/HLS) then maybe its
better to adopt it. Continually redesigning a perfect CSS2 is probably
not the best use of people's time given that the target is legacy
browsers anyway and that most folks only seem interested in the
combination of CSS with HTML.

>> > If one person feels strongly against an issue it's hard to get it
>> > through the REC process.

I know. Thats why my color names proposal did not make it into CSS1,
or into CSS2.

SP> Personally I didn't care enough about SVG to fight.

Noted.

SP> I care enough about CSS that I don't want to see it spoiled.

Well, I used to care about pure design in CSS too which is why I
complained about the poor design of HSL so much. But now it seems the
trend is more to document existing practice rather than design a good
thing - same as happened in HTML 3.2 and 4.0. Pragmatics and a stab at
interoperability wins over a pure but unused design. Particularly
since the number of real XHTML+CSS2 implementations is so small.

However, I do care about SVG and don't want to see it spoiled, since
it is part of the one chance we have of getting a real XML web client
base rather than the legacy cruft that we have now.

>> However, if, as you say, it's hard to get it through the REC process, then
>> presumably SVG 1.1 has similar issues to CSS3 color with respect to the
SP> X11
>> colors, since neither is a REC yet.

But SVG 1.0 is.

>> Therefore, these two groups must resolve this matter one way or
>> another in order to proceed with both of these specs.

SP> Only if one agrees that SVG and CSS have to be consistent.

I agree that a fallback strategy would be for SVG not to bother
referencing the CSS3 module. I would prefer to attempt to maintain a
shared formatting properties space, given that so much effort has been
put into it notably by Steve Zilles.

However, while this thread is focusing on SVG, note that legacy HTML
browsers have been supporting the "X11" color names set for a good
number of years (since at least 1996, probably earlier, and suggested
for inclusion in CSS in July 1996 [5]) and I believe that this was the
*primary* reason for adding this to CSS3 - documenting existing,
interoperable practice.

[1] http://lists.w3.org/Archives/Public/www-style/1996Feb/0006.html
    http://lists.w3.org/Archives/Public/www-style/1996Feb/0020.html
[2] http://lists.w3.org/Archives/Public/www-style/1996Feb/0016.html
    http://lists.w3.org/Archives/Public/www-style/1996Feb/0019.html
[3] http://lists.w3.org/Archives/Public/www-style/1996Feb/0022.html
[4] http://lists.w3.org/Archives/Public/www-style/1996Apr/0029.html
[5] http://lists.w3.org/Archives/Public/www-style/1996Jul/0166.html


-- 
 Chris                            mailto:chris@w3.org
Received on Wednesday, 29 May 2002 13:44:22 GMT

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