W3C home > Mailing lists > Public > www-style@w3.org > June 2002

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

From: Chris Lilley <chris@w3.org>
Date: Thu, 6 Jun 2002 19:59:27 +0200
Message-ID: <119195244859.20020606195927@w3.org>
To: www-style@w3.org, "Robert Hess" <roberth@microsoft.com>

On Wednesday, June 5, 2002, 4:43:37 PM, Robert wrote:


RH> I've written a number of articles about colors, including the web
RH> colors, as well as touching upon the X11 named colors. I one time built
RH> up some calculation tables to rank/sort the various colors of the 216
RH> web colors, and from that created a chart that illustrated the fairly
RH> even distribution that these colors provide across the HSL space (see
RH> the second chart in:
RH> http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnwebge
RH> n/html/colorpick.asp),


Which proves exactly nothing.

Since HSL space is perceptually highly non-uniform, even distribution
in HSL tells you nothing about the distribution of the actual colors.

Since HSL is merely a polar form of RGB and since the allegedly 'Web
safe' colors are merely a 6x6x6 grid on the RGB cube, naturally the
web-safe colors are evenly distributed in HSL.

To see whether the colors are in fact evenly distributed, the easiest
approach would be to plot them in Lab. Many better, but more
complicated, approaches are also possible using more advanced color
appearance models and color difference metrics.

An example, which I presented in 1994 at the fourth WWW conference in
Boston, would be figure seven in
http://www.w3.org/Conferences/WWW4/Papers/53/gq-alloc.html linked from
http://www.w3.org/Conferences/WWW4/Papers/53/gq-boston.html.

Note the enormous spacing of dark greens in the 6x6x6 cube, for example.

Woohoo, 1996 now 1994. At this rate, we will hit 1931 - where it all
started - fairly soon.

RH> I then thought it might be interesting to perform
RH> the same calculations on the X11 colors and see if I could build up a
RH> similar chart to help show the distribution pattern.

RH> It was -hideous-.

Which again, tells you nothing.


-- 
 Chris                            mailto:chris@w3.org
Received on Thursday, 6 June 2002 14:00:17 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Monday, 27 April 2009 13:54:14 GMT