Re: Rationale for using RGB Values?

After a *lot* of searching, I found:
http://lists.w3.org/Archives/Public/w3c-wai-gl/1999JanMar/0235.html
The recommendation for using RGB values in CSS instead of colour names
comes from Hakon himself, at http://www.w3.org/WAI/GL/css2em.htm
[[[
Use numbers, not names, for colors
Color names also vary from one platform to another. CSS supports 16 color
names: aqua, black, blue, fuchsia, gray, green, lime, maroon, navy, olive,
purple, red, silver, teal, yellow, white. Some browsers have chosen to
support additional color names, but there is no definite list. Therefore,
you should: use numbers, not names, for colors . Color names may seem
friendlier than the somewhat cryptic RGB notation introduced in the
previous chapter, but the Web has yet to see the ultimate list of color
names that work on all platforms. Color numbers, on the other hand, can
easily be interpreted by any browser.
You may have to experiment a bit, to get the exact color you want, or find
some software that helps you mix the right colors. CSS supports the
hexadecimal notation ("#FF0000" and "#F00") and also some other notations
that may be easier to use. The following two rules both set the color of h1
elements to brown (50% red, 50% green, 0% blue):
H1 {color: #808000}
H1 {color: rgb(50%,50%,0%)}
]]]

Which seems fine and self-explanatory to me: I've BCC'd this to the
original commentor.

Kindest Regards,
Sean B. Palmer
http://infomesh.net/sbp/
"Perhaps, but let's not get bogged down in semantics."
   - Homer J. Simpson, BABF07.

----- Original Message -----
From: Charles McCathieNevile <charles@w3.org>
To: Sean B. Palmer <sean@mysterylights.com>
Cc: <w3c-wai-gl@w3.org>
Sent: Saturday, December 30, 2000 3:41 PM
Subject: Re: Rationale for using RGB Values?


> Hmmm. Probably the best way to get the answer is to sift back through old
> minutes and mail archives which predate the first introduction of the
> technique. So start sifting back through revisions of the techniques
> document...
>
> The only reason I can think of is that it is theoretically a little
easier to
> deal with color values that are RGB automatically. In particular, there
is no
> need to write the case statement, or array search, that associates a
numeric
> value with colours. Which seems a little tenuous to me. In terms of
> internationalisation, they are both effectively opaque strings. But then
so
> are the supposedly mnemonic names for most HTML elements (not that "a"
ever
> strikes me as very mnemonic, althoug at least it is easy to write).
>
> Any other pearls of wid=sdom (or has someone done the actual research
> suggested above?)
>
> Charles McCN
>
> On Fri, 29 Dec 2000, Sean B. Palmer wrote:
>
>   <lang xml:lang="en">
>   I was asked a question about the rationale for the WCAG CSS Techniques
[1]
>   telling people to use qualified colours (RGB values) rather than names.
The
>   only reason I could think up was that names aren't as widely supported
as
>   RGB values, and you can't get the exact colour that you want. Please
note
>   that the Techniques document provides no explanation whatsoever for
using
>   RGB rather than a name.
>   I was asked this question about three days ago. It has taken me all
that
>   time to realise that I'm on GL, so I only have to raise the point
(duh!)
>
>   [1] http://www.w3.org/TR/WCAG10-CSS-TECHS/
>
>   The commenter noted that it might be a mistake, but since it was not
>   explained he could not comment further!
>
>   Kindest Regards,
>   Sean B. Palmer
>   http://infomesh.net/sbp/
>   "Perhaps, but let's not get bogged down in semantics."
>      - Homer J. Simpson, BABF07.
>   </lang>
>
>
> --
> Charles McCathieNevile    mailto:charles@w3.org    phone: +61 (0) 409 134
136
> W3C Web Accessibility Initiative
http://www.w3.org/WAI
> Location: I-cubed, 110 Victoria Street, Carlton VIC 3053, Australia
> until 6 January 2001 at:
> W3C INRIA, 2004 Route des Lucioles, BP 93, 06902 Sophia Antipolis Cedex,
France
>
>

Received on Saturday, 30 December 2000 12:51:41 UTC