Further to a post in another thread, and the point highlighted by Simon relating to colour blindness.

As I'm reluctantly about to embark on putting together a couple of pages, I'd like to know if there are any conventions for making sites accessable to the visually impaired, such as which colour goes with which (apart from the requirement that you don't have to wear sunglasses to view the pages) and if there are any other pitfalls similar to this that should be avoided.

One of the things you are supposed to do to support access for the visually impaired is to allow variable sized fonts instead of fixed size fonts. (I.e. use [Font-Size = 3] instead of [Font-Size : 12pt] [this is not exact HTML, but I hope you understand the meaning.]) The effect is to allow the user to increase the font size to bring it up to a readable level.
(By the way, I set a very poor example in this respect!)

For colour blindness, avoid red on green or green on red.
For "colour confusion" (this is the lesser form of colour blindness, which I have), avoid large mixes of colour.

Use the underline convention for links (and don't use underline for anything else), which makes a link clear regardless of colour.

Avoid excessive background graphics (because colours in the background impair the legibility of the text). [Again, I plead guilty.]

[I also plead guilty to not checking my posts after I've made them; the above now makes more sense than it did when first posted.]

I'd check out http://www.rnib.org.uk/ website, there's info there.

Its simple!

Just make sure that the colours you use are well matched. I have prorbably said this a hundred times but if you are sensible with colours and layout then everyone will be fine.

As for background pictures, I don't honestly think I have seen any amdram site that uses a background picture well. I have to be honest, it's either the time taken to load a HUGE image or you cannot read the text because of this massive background picture looking right at you.

If you are going to use a background picture, make sure it is extremely faint and in no way intereferes with the text, also make sure that it loads quick and tiles well.

I am colour blind, I am terrible, however if the site is well laid out and the obvious combinations of red and green are avoided then there are no problems for me.

As for font sizes, I think you will find that there are more and more visually impaired people that have software installed on their machines to enlarge windows etc. I would read the information from the RNIB!

I find that braille only has a very limited appeal.

First, may I say that I think it's brilliant that you are considering accessibility at the start. So many sites tack on a few token bits at the last moment, while leaving most of the site completely unusable ("professional" sites for big companies are often the worst offenders).

If you are worried about people with colour blindness having difficulties with your colour scheme, try Visicheck, which will show you a simulation of how your whole page or images will look to a person with any of three common forms of colour blindness.

For really thorough guidelines on website accessibility, try the W3C guidelines:
Web Content Accessibility Guidelines 1.0.

In general:

- Don't use small fonts. People with perfectly reasonable eyes may suffer if they have a high resolution display which makes everything smaller.
- Use a high contrast between your background and text. This means dark on pale, or vice versa - bright turquoise on puce need not apply!
- Try not to overuse tables as a layout tool, say for getting multiple columns of text. It's awkward if people need a big font size, and also very hard for audio browsers to interpret.

Hope that helps.

--
Cal

Having just attended a course on professional presentation, really aimed at Powerpoint presentations, I am informed that white font on blue is the absolute easiest on the eye, and that using red in any quantity will lose attention very quickly.

Also that using Arial font may be less interesting when putting it together but is the easiest to read. And that as our brains are attuned to reading left to right, only centre things if you have to. All fonts that can should be blocked to the left.

Moving graphics shouldn't last more than 10 seconds, and don't use animations that detract from the title of your page - in other words make sure you page title is the first thing that is noticed by whoever opens the site.

Not tried it yet, not sure how to make a web site (I did an ancient html one about 8 years ago which is still on line somewhere but that's about it!) but am keen to have a go.

White on blue? Ooh, no. It's fine for Powerpoint presentations where the text is very large, but on a web site I find white lettering on a dark background much harder to read than the other way round.

Again for web sites, Verdana is supposed to be easier to read than Arial.

I think agree with Paul on this one!

In my personal opinion dark backgrounds on sites look far less professional than white background or light colour background sites.

I don't think I can name many big company sites that have a dark background but there are a few.

Again it depends on the audience that you are attempting to attract, younger interenet audiences would probably prefer the darker backgrounds and white writing however overall I would say that nobody has a problem with white background and dark writing!

Just like to say, thanks to you lot -we have finally got round to building a website for our group!!! (This forum has a lot to answer for!!! )

Byeeeeee