Re: HTML 3.2 PR color value syntax

Peter Flynn (pflynn@curia.ucc.ie)
12 Nov 1996 10:52:56 +0000 (GMT)


Date: 12 Nov 1996 10:52:56 +0000 (GMT)
From: Peter Flynn <pflynn@curia.ucc.ie>
Subject: Re: HTML 3.2 PR color value syntax
To: www-html@w3.org
Message-id: <199611121052.KAA09673@curia.ucc.ie>

> > 	   * Popular graphics tools do not support this format.
> > 
> > That's simply not true.
> 
> 	OK, name three major Mac/PC graphics programs that support
> it. I named three major ones that don't.

I can only name the one I use on a PC, one of the most popular,
PaintShop Pro, which displays the RGB colour value at the bottom edge
of the frame whenever you click the eyedropper on a colour. I also use
xv but that's UNIX.

But if your complaint is specifically about the hex expression rather 
than the use of RGB values, then you're quite correct, it's not common
outside the technical field. I just don't see it as a problem, but if
others do, then it should be changed as you suggest.

> 	Right, this should be RGB as well. This is really only
> for Macintosh compatibility. This percentage syntax is not anywhere
> near as important as the RGB integer syntax, IMHO, but since most
> people use Macs to design Web art these days...

Are you saying that the % spec is proportionally congruent with the
0-255 range, with 0:0/100:255 ? I don't have a Mac, so I'm not familiar 
with Mac expressions, but this looks every bit as weird as the hex 
format. Should be trivial to support though.

> 	I won't then, but in that case, where are such browser
> implementation standards defined? 

That's one of the problems: they're not. HTML doesn't define a colour
syntax, it simply allows some specification of colour and leaves it to
the application to decide how to implement it. As it was implemented
first by programmers, they picked the most convenient format for them:
hex RGB. If designers want something different, it's up to them to make
the case and persuade the programmers.

> Do you mean that the whole state
> of things is that I can write HTML that two browsers validate perfectly
> with the same DTD and have it completely break in one and not in the
> other? 

Absolutely. Except that browsers don't perform any validation at all,
you need to use a parser for that.  Saying <font color="courier"
face="12"> is perfectly valid HTML, it's just incorrect usage. 

The same is true of any computer language: I can set a string value
(which is basically how COLOR and FACE are defined) to any value I
like, but if I want it to have meaning, it has to be a value the
application understands.

It didn't have to be: COLOR could easily have been defined as a limited
set of 16 or 256 colour names, or as an integer, or whatever. It just
wasn't, because the inventors of <FONT> and BGCOLOR etc either wanted
to leave it open to the browsers to interpret in whatever way they felt
best (or possibly they simply didn't understand enough of the language
[SGML] to do the job any other way).

Don't shoot the pianist :-)

///Peter