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Thread: Re: Color contrast in links -- is it important?
Number of posts in this thread: 15 (In chronological order)
From: Phil Teare
Date: Fri, Apr 20 2007 10:40AM
Subject: Re: Color contrast in links -- is it important?
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What lots of folk forget/don't know/wrongly assume to be unimportant is that
some users need low contrast. Many dyslexic users, those with Irlen's,
scoptic sensitivity, visual stress. And we (I'm one) are covered by the
DDA.
So there is no simple solution, and current regs do not reflect this :(
Best
Phil
--
Phil Teare,
Technical Director & Lead Developer,
http://www.talklets.com from Textic Ltd.
(44) [0] 77 68479904
From: tedd
Date: Fri, Apr 20 2007 10:50AM
Subject: Color contrast in links -- is it important?
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Hi gang:
Question for the day: Color contrast in links -- is it important?
Now before everyone jumps on the bandwagon and tells me why contrast
is important, does anyone really have problems with the color
contrast of links? Remember there are four states of a link and if it
matters, then each link has to be evaluated for contrast in each
state (link, visited, active, hover).
So, what say you?
Cheers,
tedd
--
-------
http://sperling.com http://ancientstones.com http://earthstones.com
From: Cheryl D Wise
Date: Fri, Apr 20 2007 11:00AM
Subject: Re: Color contrast in links -- is it important?
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It is also users on portable machines with power saving settings that have
the screen at less than 100% brightness.
Some that are okay but not good contrast are not acceptable at 80%
brightness a very common power saver setting.
Cheryl D Wise
MS MVP FrontPage
http://by-expression.com
Foundations of Microsoft Expression Web:The Basics and Beyond
From: tedd
Date: Fri, Apr 20 2007 11:10AM
Subject: Re: Color contrast in links -- is it important?
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At 11:52 AM -0500 4/20/07, Cheryl D Wise wrote:
>It is also users on portable machines with power saving settings that have
>the screen at less than 100% brightness.
>
>Some that are okay but not good contrast are not acceptable at 80%
>brightness a very common power saver setting.
>
>Cheryl D Wise
Cheryl:
Yes, but isn't that a user's choice? That's not something that we can
plan for, is it?
I use the following link a lot. It's a great link into understand
color contrast.
http://gmazzocato.altervista.org/colorwheel/wheel.php
If you play with it, you'll see that there is a very small area of
"OK!" settings.
If we also had to consider power savings on laptops, then that area
would be reduced even more, is it reasonable to consider this?
Cheers,
tedd
--
-------
http://sperling.com http://ancientstones.com http://earthstones.com
From: Moore, Michael
Date: Fri, Apr 20 2007 11:20AM
Subject: Re: Color contrast in links -- is it important?
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Question for the day: Color contrast in links -- is it important?
Now before everyone jumps on the bandwagon and tells me why contrast is
important, does anyone really have problems with the color contrast of
links? Remember there are four states of a link and if it matters, then
each link has to be evaluated for contrast in each state (link, visited,
active, hover).
Tedd
Well yes of course color and contrast are as important for links as it
is for other text on the page. A recent real world example of this
failure that I can think of is a occurred at a major university here,
where they chose to have the link color match the school colors.
Unfortunately this color did not provide sufficient contrast for some
color blind users to be able to distinguish links from the rest of the
content on the page. They have since mitigated the problem by using a
heavier font-face and darkening the color somewhat.
I would disagree that contrast matters too much for all of the states
though.
1. link definitely
2. visited yes, otherwise the links will disappear for some
users
3. active, probably not - this is a very temporary state when
the user is actually activating the link if they are doing this they
have already found it.
4. hover - probably, but not quite as critical as the link or
visited states.
In addition the focus state, (not recognized by all browsers but hacks
do exist to get this to work) should have the same effect as the hover
state. This way keyboard users get the same benefit as those using a
mouse.
That's my 2 cents anyway.
Mike Moore
Accessibility Specialist
Texas Department of Assistive and Rehabilitative Services (DARS)
From: tedd
Date: Fri, Apr 20 2007 11:30AM
Subject: Re: Color contrast in links -- is it important?
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At 11:48 AM -0500 4/20/07, Moore, Michael wrote:
>Question for the day: Color contrast in links -- is it important?
>
>Now before everyone jumps on the bandwagon and tells me why contrast is
>important, does anyone really have problems with the color contrast of
>links? Remember there are four states of a link and if it matters, then
>each link has to be evaluated for contrast in each state (link, visited,
>active, hover).
>
>Tedd
>
>Well yes of course color and contrast are as important for links as it
>is for other text on the page. A recent real world example of this
>failure that I can think of is a occurred at a major university here,
>where they chose to have the link color match the school colors.
>Unfortunately this color did not provide sufficient contrast for some
>color blind users to be able to distinguish links from the rest of the
>content on the page. They have since mitigated the problem by using a
>heavier font-face and darkening the color somewhat.
>
>I would disagree that contrast matters too much for all of the states
>though.
> 1. link definitely
> 2. visited yes, otherwise the links will disappear for some
>users
> 3. active, probably not - this is a very temporary state when
>the user is actually activating the link if they are doing this they
>have already found it.
> 4. hover - probably, but not quite as critical as the link or
>visited states.
>
>In addition the focus state, (not recognized by all browsers but hacks
>do exist to get this to work) should have the same effect as the hover
>state. This way keyboard users get the same benefit as those using a
>mouse.
>
>That's my 2 cents anyway.
>
Mike Moore
Mike:
Thanks for your feedback -- I suspected it was, but wanted to know IF
this was to be considered an issue or not. For example --
http://fae.cita.uiuc.edu/about.php
-- is a site that advocates disability issues and best practices, but
their links don't pass the contrast measure. So, either they don't
know it's an issue; or they don't think it's an issue; or it's not
enough of an issue to practice it. I don't know, but it's there.
Also, we as developers don't have to address the link issue at all
and let the user's browser default to whatever that is, right? Could
that be a solution?
Also, you speak of using a heaver font -- does that work? Is font
size an element that can be used to offset the color contrast
requirement? For example, is color-contrast different for a font-size
1em and compared to font-size 1.2em?
Cheers,
tedd
--
-------
http://sperling.com http://ancientstones.com http://earthstones.com
From: Cheryl D Wise
Date: Fri, Apr 20 2007 11:50AM
Subject: Re: Color contrast in links -- is it important?
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As long as you stick to the "good" contrast it shouldn't be a problem since
as you said it is a user's choice but the ones I've seen are the borderline
type even at 100% brightness.
Cheryl D Wise
MS MVP FrontPage
http://by-expression.com
Foundations of Microsoft Expression Web:The Basics and Beyond
From: Keith Parks
Date: Fri, Apr 20 2007 12:20PM
Subject: Re: Color contrast in links -- is it important?
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On Apr 20, 2007, at 10:26 AM, tedd wrote:
> I use the following link a lot. It's a great link into understand
> color contrast.
>
> http://gmazzocato.altervista.org/colorwheel/wheel.php
>
> If you play with it, you'll see that there is a very small area of
> "OK!" settings.
It seems like you're getting into a different issue here. That color
wheel is aimed at checking text/background contrast, right? Whereas
originally you were talking about having sufficient difference
between two *foreground* text color, no?
> Also, we as developers don't have to address the link issue at all
> and let the user's browser default to whatever that is, right? Could
> that be a solution?
If you are not altering the link presentation at all, then I would
think yes, it would be a non-issue in that context.
> Also, you speak of using a heaver font -- does that work? Is font
> size an element that can be used to offset the color contrast
> requirement? For example, is color-contrast different for a font-size
> 1em and compared to font-size 1.2em?
At least in terms of the 508 spec's, "...information conveyed with
color is also available without color, for example from context or
markup."
Since part of the "information" you are trying to communicate is that
one bit of text is a link, while another bit is not, then if your
*only* differentiation between links and non is color, even if it
does pass the contrast tests, you'd still come up short. A larger
font would theoretically qualify as a non-color distinction, but
depending on if the user has text anti-aliasing, what their monitor
resolution is, etc, I'm not sure that a .2em difference would even be
distinguishable in many cases.
-Keith
******************************
Keith Parks
Graphic Designer/Web Designer
Student Affairs Communications Services
San Diego State University
San Diego, CA 92182-7444
(619) 594-1046
mailto: = EMAIL ADDRESS REMOVED =
http://www.sdsu.edu
http://www.sa.sdsu.edu/communications
----------------------------------------------------------
A riddle wrapped in a mystery inside an enigma, served with a side of
slaw.
From: tedd
Date: Fri, Apr 20 2007 4:40PM
Subject: Re: Color contrast in links -- is it important?
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At 11:15 AM -0700 4/20/07, Keith Parks wrote:
>On Apr 20, 2007, at 10:26 AM, tedd wrote:
>
>> I use the following link a lot. It's a great link into understand
>> color contrast.
>>
> > http://gmazzocato.altervista.org/colorwheel/wheel.php
>>
>> If you play with it, you'll see that there is a very small area of
>> "OK!" settings.
>
>It seems like you're getting into a different issue here. That color
>wheel is aimed at checking text/background contrast, right? Whereas
>originally you were talking about having sufficient difference
>between two *foreground* text color, no?
Interesting, I see what you are talking about, namely the difference
between two foreground text, which raises a problem I had not
considered. In other words, how much color-contrast difference should
here be between all the states of the link and as compared to the
surrounding standard text -- that's a big consideration.
I was talking about the color-contrast of links against the
background and if those elements should be treated the same as any
other text against the same background. I think the consensus is
"yes". But, you raise a question that may not have a solution.
The solution to the problem you raised must provide enough contrast
between all states of the link as well as being different than
standard text. That will certainly narrow the field of possibilities
down considerably. You do have any references on that?
> > Also, you speak of using a heaver font -- does that work? Is font
>> size an element that can be used to offset the color contrast
>> requirement? For example, is color-contrast different for a font-size
>> 1em and compared to font-size 1.2em?
>
>At least in terms of the 508 spec's, "...information conveyed with
>color is also available without color, for example from context or
>markup."
"Without color" what does that mean? Black on white, or what? Without
color means transparent to me.
Also, is it acceptable to have a "contrast-link" setting for those
who need it? Will that satisfy the section 508 spec's? Or, is this
supposed to be a "one-size fit all" sort of thing?
>Since part of the "information" you are trying to communicate is that
>one bit of text is a link, while another bit is not, then if your
>*only* differentiation between links and non is color, even if it
>does pass the contrast tests, you'd still come up short. A larger
>font would theoretically qualify as a non-color distinction, but
>depending on if the user has text anti-aliasing, what their monitor
>resolution is, etc, I'm not sure that a .2em difference would even be
>distinguishable in many cases.
That example I gave was a 20 percent increase in the size of the
font. Okay, let's try this again, what if one paragraph font size is
twice the font size of a different paragraph? Do they fall under
different contrast guidelines?
Thanks for your time and comment.
Cheers,
tedd
--
-------
http://sperling.com http://ancientstones.com http://earthstones.com
From: Keith Parks
Date: Fri, Apr 20 2007 5:50PM
Subject: Re: Color contrast in links -- is it important?
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On Apr 20, 2007, at 2:54 PM, tedd wrote:
> The solution to the problem you raised must provide enough contrast
> between all states of the link as well as being different than
> standard text. That will certainly narrow the field of
> possibilities down considerably. You do have any references on that?
>
Nope.
> "Without color" what does that mean? Black on white, or what?
>
Yeah, that's how I try and think of it. "If this was on a grey-scale
only monitor, would whatever distinction or information that I'm
using color to create still come through?" That's why I almost always
leave the underlines on my links, especially those that are inline
with the text flow.
But then there is also the "context" method. If you have a section of
your page with a heading "Menu" or "Contents" or whatever, and under
that you have some words, it seems to me those words could look like
regular text (black, no underline, or they could be graphics for that
matter) and the context within your design *should* communicate that
they are links.
> Also, is it acceptable to have a "contrast-link" setting for those
> who need it? Will that satisfy the section 508 spec's? Or, is this
> supposed to be a "one-size fit all" sort of thing?
>
If you mean a user option to change the presentation colors,
contrast, size, etc., I'm not sure. Certainly my goal is the "one
size" approach, even if it means an occasional compromise on the
design side.
> That example I gave was a 20 percent increase in the size of the
> font. Okay, let's try this again, what if one paragraph font size
> is twice the font size of a different paragraph? Do they fall under
> different contrast guidelines?
>
I don't think there is a specific "contrast" guideline in 508 (in W3C
maybe?), only the point about info being conveyed with color. I think
the color contrast recommendation like the color wheel you linked to
are more "best practices, practical solutions" to address color
vision issues.
In terms of font size, I would think 2X normal size type would be
quite noticable. ;^)
But assuming there is some content distinction you are trying to
communicate by having one paragraph be twice as big, remember that
you should also build that distinction in through the structural
markup. Either tag it as <strong> or <em> (emphasis), then use CSS to
display that tag twice normal size.
My 2¢,
Keith
******************************
Keith Parks
Graphic Designer/Web Designer
Student Affairs Communications Services
San Diego State University
San Diego, CA 92182-7444
(619) 594-1046
mailto: = EMAIL ADDRESS REMOVED =
http://www.sdsu.edu
http://www.sa.sdsu.edu/communications
----------------------------------------------------------
(Objects on your screen may be closer than they appear)
From: Randall Pope2
Date: Sat, Apr 21 2007 11:10AM
Subject: Re: Color contrast in links -- is it important?
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Hi Everyone,
I have been watching this list for quite sometimes and learned a lot of you
all. I'm Randall Pope who is deaf-blind (meaning that I'm both severely
hard of hearing and legally blind with some usable vision). I'm a webmaster
for the American Association of the Deaf-Blind and working on a new web
design which will be more accessible than the current one at http://aadb.org
. While I'm not happy with my first design, it was certainly a big learning
experience for me. I will get to some other accessible issues later. Now
the question on color contrast in links.
As a low vision person like myself, I feel there is a big need for color
contrast in the web design. As some of you may already know, less than 10%
of the legally blind population is actually total blind. I believe about
35% of the blind population use some kind of accessible devices such as JAWS
to access the information on the web but I'm not 100% sure about this. But
I do know a good number of low vision readers do use their vision without
any kind of assisting devices.
As a low vision user, my suggestion of the four states of the links in
regards to color contrast:
Link = very important. The underline does help but sometimes I cannot tell
the difference from a content underline from the link underline. Many
times, I have click on underline words only to find out that is not a link
after clicking on it several times, not to mention of being annoyed. Plus
the color contrast between the link and the content does help a lot.
Visited = important. Many times I get confused which page that I visit
because the website does not offer a different color. Also a contrasted
color background is a big help in finding the visited links.
Active = not important. I must confess that I don't quite understand the
purpose of having this function or make it work for accessible reason.
Someone may need to advise me on this one.
Hover = very important. This feature really helps me assure that my mouse
in the right position before clicking. Without the hover many times I did
not have the mouse in proper position which resulted going to the wrong
page.
Many thanks for the question and hope some of you will have an idea what I
see. I do have one big issue: Sign Language users who use American Sign
Language as their first language. There are quite a few deaf who cannot
read English writing well but can understand the content through sign
language.
Take care,
Randy Pope
From: Emma Duke-Williams
Date: Sat, Apr 21 2007 4:00PM
Subject: Re: Color contrast in links -- is it important?
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On 21/04/07, Randall Pope2 < = EMAIL ADDRESS REMOVED = > wrote:
>
> As a low vision person like myself, I feel there is a big need for color
> contrast in the web design. As some of you may already know, less than 10%
> of the legally blind population is actually total blind. I believe about
> 35% of the blind population use some kind of accessible devices such as JAWS
> to access the information on the web but I'm not 100% sure about this. But
> I do know a good number of low vision readers do use their vision without
> any kind of assisting devices.
Relating this comment back to the point about some users finding too
much contrast difficult, does any one have any statistics about the
numbers of users who fall into these groups - and also what other aids
they might be using. (I know a friend's child had difficulty reading,
it wasn't dyslexia, nor irlen lens sydrome; they weren't quite sure
exactly what. Whatever the problem, and it doesn't really matter,
tinted glasses helped him - he used them for everything; PC, books
etc. )
>
> As a low vision user, my suggestion of the four states of the links in
> regards to color contrast:
>
> Link = very important. The underline does help but sometimes I cannot tell
> the difference from a content underline from the link underline. Many
> times, I have click on underline words only to find out that is not a link
> after clicking on it several times, not to mention of being annoyed. Plus
> the color contrast between the link and the content does help a lot.
The thing I'd say here, is that anything that's not a link shouldn't
be underlined. Given that people do have differing needs when it comes
to contrast; and, as others have pointed out, it's not the contrast
between foreground & background that is important for links, it's the
contrast between different words.
>
> Visited = important. Many times I get confused which page that I visit
> because the website does not offer a different color. Also a contrasted
> color background is a big help in finding the visited links.
Yes.
>
> Hover = very important. This feature really helps me assure that my mouse
> in the right position before clicking. Without the hover many times I did
> not have the mouse in proper position which resulted going to the wrong
> page.
As someone with no disability, I'd agree with that. The sites that use
hover & put a coloured background under the word - make it very easy
to see what's a link.
>
> Many thanks for the question and hope some of you will have an idea what I
> see. I do have one big issue: Sign Language users who use American Sign
> Language as their first language. There are quite a few deaf who cannot
> read English writing well but can understand the content through sign
> language.
Do you mean having essentially an image based page, with images of
different signs (does ASL have a different grammar to spoken English,
in the way that BSL does) - which would, in fact be the equivalent of
producing the page in French or any other foreign language. Or, would
you envisage having videos of someone signing the information?
I guess the ideal would be to have both text based and at least one
other. Would I be right in also assuming that, like many deaf British
Adults who have grown up with BSL as their first langage, native ASL
users tend to have reading (of English) levels below the average
anyway? ANd, I guess, some will come from homes where neither ASL nor
English is the first langauge of the rest of the household. A
multilingual audience!
Emma
--
Blog: http://www.tech.port.ac.uk/staffweb/duke-wie/blog/
From: tedd
Date: Sun, Apr 22 2007 7:10AM
Subject: Re: Color contrast in links -- is it important?
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At 12:58 PM -0400 4/21/07, Randall Pope2 wrote:
>As a low vision user, my suggestion of the four states of the links in
>regards to color contrast:
>
>Link = very important. The underline does help but sometimes I cannot tell
>the difference from a content underline from the link underline. Many
>times, I have click on underline words only to find out that is not a link
>after clicking on it several times, not to mention of being annoyed. Plus
>the color contrast between the link and the content does help a lot.
>
>Visited = important. Many times I get confused which page that I visit
>because the website does not offer a different color. Also a contrasted
>color background is a big help in finding the visited links.
>
>Active = not important. I must confess that I don't quite understand the
>purpose of having this function or make it work for accessible reason.
>Someone may need to advise me on this one.
>
>Hover = very important. This feature really helps me assure that my mouse
>in the right position before clicking. Without the hover many times I did
>not have the mouse in proper position which resulted going to the wrong
>page.
Randall:
Considering that there are simply not enough shades of black to show
the differences between the different states of links, it's my
conclusion it's really not possible to comply with WCAG guidelines on
this matter.
However, there are other techniques one can employ to highlight
differences in link states. I would like to get your opinion of the
ones presented here:
http://f6design.com/journal/2007/04/14/styling-links/
Do any of these meet your needs?
Cheers,
tedd
PS: Active link status simply means what the link "looks like" upon
activation. Some people like to see a momentary visual conformation
when they click something. I don't think it's important for
disability issues, but all people are the same. I'm sure there is
some form of conformation of an action for you as well.
--
-------
http://sperling.com http://ancientstones.com http://earthstones.com
From: Patrick H. Lauke
Date: Sun, Apr 22 2007 7:30AM
Subject: Re: Color contrast in links -- is it important?
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tedd wrote:
> PS: Active link status simply means what the link "looks like" upon
> activation. Some people like to see a momentary visual conformation
> when they click something. I don't think it's important for
> disability issues, but all people are the same. I'm sure there is
> some form of conformation of an action for you as well.
That's the sort of thing that, in my mind, should be the responsibility
of the user agent. For instance, I seem to remember that in IE you can
have an audible "click" sound for each link activation...this could
conceivably be extended to non-aural types of confirmation at browser
level as well.
P
--
Patrick H. Lauke
From: Phil Teare
Date: Sun, Apr 22 2007 10:30AM
Subject: Re: Color contrast in links -- is it important?
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Hi Emma
> Relating this comment back to the point about some users finding too
> much contrast difficult, does any one have any statistics about the
> numbers of users who fall into these groups - and also what other aids
> they might be using. (I know a friend's child had difficulty reading,
> it wasn't dyslexia, nor irlen lens sydrome; they weren't quite sure
> exactly what. Whatever the problem, and it doesn't really matter,
> tinted glasses helped him - he used them for everything; PC, books
> etc. )
>
These figures are approx and sometimes mid points between two popular
figures...
In the UK approximately 5% of the entire population are severely effected by
dyslexia, 10% of the population is dyslexic to a degree that they would be
clearly diagnosed as such, and thereby acquire legal rights for
accomodation. The tail drags on for another 5-10% of the population.
80%+ of dyslexics have some form of visual 'lag' which is or is similar to
Irlens.
Some (but few) have Irlens but no dyslexia. There's a great deal of
comorbidity, but they are different conditions.
50%+ of those incarcerated have dyslexia! Think of the social cost of not
accommodating their differences in society. I once estimated it at more than
£1bn p.a. in the UK. The DI then backed this estimate.
Compare these figures to those for v.i. users in the general populus and we
can see that the issues is certainly not less significant than v.i. Clearly
quantifying social need is subjective at best, but like I say, I hope you'd
agree that this is a very important issue that is not mentioned in the WACG
at all.
High and low contrast options ought to be advised by the standards and
guidlines IMNSHO
I could poss dig out references for the above figures, but you'll find them
as quickly as me, with google. For excellent work in this area look for Prof
Jon Stein's work at Oxford (I believe he headed an investigation funded by
Tintavision - I know for a fact that here was perfectly impartial,
disagreeing with a great many of Tintavision's assumptions in his finding,
by finding some very interesting fact in the process, including a multi
sensory deficit at discerning information at around 2hz, even in touch,
amongst dyslexic individuals).
Hope this helps,
-
Phil Teare,
Technical Director & Lead Developer,
http://www.talklets.com from Textic Ltd.
(44) [0] 77 68479904