- From: Doyle Burnett <dburnett@sesa.org>
- Date: Wed, 10 Dec 2003 15:46:26 -0900
- To: Wendy Chisholm <wendy@w3.org>, Tom Croucher <tcroucher@netalleynetworks.com>, W3C Web Content <w3c-wai-gl@w3.org>
To The Group - Wendy, thanks for sending these two links to resources related to color deficiencies. Given the recent "stuff" we've been working on related to guideline 1.6 - this is likely valuable information. I did some experimenting with both sites and found "Juicy Studio" (http://www.juicystudio.com/services/colourcontrast.asp) to be the most useful of the two resources. And, if we go that route, it does give their algorithm such that a person can evaluate their use of hexadecimal color values related to brightness and contrast. I did, however, find the contrast algorithm on Juicy Studio to be a bit confusing but maybe that's just me. On the other hand, the resource at - http://colorfilter.wickline.org/ did not yield true color renditions of (at least) my own color issues. The site, when using the red/green color blindness link indicated that I'd see red as green - this is just not accurate (in my case). Please note, I say in my case as I really do think that there are too many variables to be certain that someone else with red/green color blindness sees what I do. Are there others in the list with color issues that can chime in on these issues? Dr. Cynthia A. Brewer (Penn State) has done a lot of work related to colors as they relate to the designing of maps. Dr. Brewer writes - Resource at: http://www.sciencedaily.com/releases/2000/04/000428082212.htm "Red/green color blindness is not simply a problem with confusing red and green. It also causes problems with an unlimited pairing of colors that fall on the confusion line. For example problems can occur distinguishing between blue-green and pink or blue-green and purple. Color-blind individuals may not be able to distinguish between olive-colored and rust-colored socks, while they could distinguish between bright green and olive socks, rust and red socks or rust and bright green socks. One way to avoid confusion is to alter the lightness and darkness of the colors. The color-blind person may still see the same color, but they can tell that the areas colored with these colors are different." "We do not know what color-blind people see," says Brewer. "Actually, we do not know what color vision looks like to anyone but ourselves. However, if a map has adjacent patches that someone sees as the same color, the information stored in the map will be inaccessible." The above paragraph really says it well - only the person with the color deficiency really knows what's being seen. Many sites that have written about color issues (red/green color blindness, in particular) have misleading information. At least one person I know (me) can easily distinguish the colors red and green - some popular web sites would have their readership believing differently. Dr. Brewer is correct, the more the brightness between two colors differ the better for (probably) most individuals with color deficiency challenges. Hence, the Juicy Studio algorithm seems to work well (at least for me). I ran many hexadecimal color variants (background/foreground) through their (Juicy Studio) online test and it worked well for me. The brightness algorithm works well (my opinion - ONLY). This whole issue is about educating web authors but it's NOT as easy as it would seem on the surface. Color blind individuals are not blind to color (one exception - achromatopsia - black and white and grey scale about one in 33,000 have this condition) - most color blind individuals see color! Anyway, Wendy, thanks for this info...I like the Juicy Studio information as a very helpful resource. I just wish there were an easy solution to this otherwise complex issue. I agree with Mat M. that we need to keep whatever we come up with simple. Doyle Doyle Burnett Education and Training Specialist Multiple Disabilities Program Special Education Service Agency dburnett@sesa.org Www.sesa.org -- On 12/10/03 12:03 PM, "Wendy A Chisholm" <wendy@w3.org> wrote: > > Juicy Studio implemented the color contrast algorithm from AERT. > Colour Contrast Analyser - > http://www.juicystudio.com/services/colourcontrast.asp > > At 07:09 AM 10/11/2003, Tom Croucher wrote: > >> http://colorfilter.wickline.org/ >> >> This looks interesting. Try running it on one of your pages. >> >> Tom
Received on Wednesday, 10 December 2003 19:45:26 UTC