WebAIM - Web Accessibility In Mind

E-mail List Archives

Re: Colour accessibility

for

From: Cliff Tyllick
Date: May 5, 2008 2:00PM

Linda, I have two thoughts.

First, let's address performance: How can you get some insight into whether the color scheme you've selected has sufficient contrast and works for people who have colorblindness? You say you're familiar with the color contrast algorithm. If you're not also familiar with these color contrast analysis tools, check them out (others might have additional suggestions):

-WAT-C's, http://www.paciellogroup.com/resources/contrast-analyser.html

-Juicy Studio's, http://juicystudio.com/services/colourcontrast.php

-VisionAustralia's, http://www.visionaustralia.org.au/info.aspx?page=628#using

I think WAT-C's analyzer might be particularly useful to you. It can show whether chosen color pairs offer sufficient contrast to be seen by individuals with any of three forms of colorblindness. This tool would give you quick answers to the question of whether your navigation offers sufficient contrast.

Second, you have another issue that may be strictly a case of preference: How red a red is too glaring a red? This sounds like a good case for a small usability test with typical customers. After all, if your preference is blue and mine is red, what does it matter which one we pick? But if your *customers* say one color or the other doesn't work for them, then shouldn't it be their call?

So set up a usability test with prototypes of Web pages using the potential color schemes. You might find out that your customers are just fine with them in red. But you might also find out that the issue _isn't_ merely preference. Show me a bright red, and I might say I like the color. But ask me to use a Web page developed with that hue as the principal color, and you might discover that I have trouble finding what's there (I like how it looks, but can I really see it?) or that I fail to complete tasks as quickly as people who use the page developed in another color scheme complete them (I will love your site's look, but I'll shop there less because I can't complete purchases quickly).

Good luck!


Cliff Tyllick
Web development coordinator
Agency Communications Division
Texas Commission on Environmental Quality
512/239-4516
<EMAIL REMOVED>

>>> "Linda Simpson" < <EMAIL REMOVED> > 5/4/2008 9:49 PM >>>
Hi,

We've been asked to change our colour scheme on our websites to fit into our
corporate colour scheme. We currently use blue, and the colour we've been
asked to change to is now red. Our site will be using a solid background,
with white for the content area (along the lines of news.com.au). Our
concern is that such a large amount of red may cause accessibility/
usability issues (we are not only talking about the background colour but
also the navigation). We may possibly have some say into the shading of the
red, but for the moment think of a nice bright colour (#A80D35).

What we need more information about is how the colour red can affect
readability. I have done research, and I know about the w3c colour contrast
algorithm. I've also had a look at the psychology of the different colours
and that red is associated with anger and intensity.

What I am wanting to know, does anyone have any failure/ success stories of
using a large amount of red on a site without it adversely affecting users.
We also wanted to know if there was a particular range that might cause
headaches in some users. I would also be interested to know of any research
into what borders on acceptable luminosity. For example, I know in a couple
of mockups that we have done, the red has been very glary, and makes
focusing on the content quite difficult. Unfortunately, this being a
personal opinion, we need the research to back it up with.

Any help that you can give will be appreciated.

Regards,
Linda