Safe web colours for colour-deficient vision

Colour is used more and more these days to help convey information. When one in twelve men have some measurable degree of colour vision deficiency, the use of certain colours in certain ways can cause difficulty when navigating web pages or software, and even total illegibility in some cases.

The key issue is to know when you are using colours which some people will not be able to differentiate - because that (for them) removes the benefit of using colour for visual cues. Colour scientists have long known which colours are confused by colour blind people, but this tends to be expressed in a way difficult for designers to utilise.

I've done a "translation" of all the colours in the standard 216-colour web-safe palette [refs 3, 11]. The colours may not show you exactly what dichromats see, but will help you to understand which colours are easily confused. This can help you to ensure that important colour cues are not lost.  

Designing Colour-Safe Web Applications

When designing web applications for colour-blindness, it's important to consider a number of things. First of all, you need to ensure that there is sufficient text to distinguish HTML buttons from one another if the colours. are similar. The best thing to do, when designing buttons, is to just make sure that you use colours that are safe for colour-blindness.

In order to deploy these web applications (especially when using JavaScript), you need to ensure that to have the proper application-monitoring tools to monitoring the consistency and load times of your applications, to ensure that the colors are correctly populated into the UI/UX as they should be. For example, if you have a table where every other row is a different color and there's a problem connecting to the application database, it's possible that this could create a problem for a colour-blind person. Dotcom Tools has an excellent list of available tools, so that's worth taking a look at.

Web Hosting Colour-Safe Applications

There's no point in spending a lot of time to create a colour-safe web application only to have it crash and not be up when people are coming to visit it. Because of this, it's important to understand that it's probably worth taking the time to seek out good hosting for your application. We've done a lot of work with colour-safe web apps, and we recommend Bluehost for hosting them, and this is for a few reasons. First of all, there are some great discounts out there that can really save you some money—so, if you're looking for a coupon code for Bluehost, we'd really recommend Web Hosting Buddy's discount as they are one of the best that we've seen. Another great reason to choose Bluehost is that they have great customer service too, so if you ever run into a problem, their technicians are great at solving them.

On top of that, they have very fast and reliable servers, and all of their hosting plans come with access to application databases like SQL, so you don't have to worry about not being able to interface your app with the proper database calls. Not to mention they are affordable too, so in our experience, you really can't go wrong with them.

An article on this topic has been published in the British Telecommunications
Engineering Journal
, Jan 1999, and the pre-print is available here as a PDF file.
(Go to the Adobe site for a free copy of the Acrobat reader)

This site includes a short Background of colour vision deficiency (10.6k of images), for common terms used here, and a brief explanation. See References for a list of places I've found interesting and/or useful during the information-gathering stage. The Related sites page has links to related tools developed by other people. The information contained on Palette files, Transforming, and Colour choice comprise the toolset.