Colour contrasts can be deceiving because we are subject to optical illusions. The video below shows how two different shades of grey are actually the same. That’s why you can’t rely on judging contrast by eye. Fortunately there are colour checkers to help with colour choices especially for websites. And why do you need colour contrast checkers? Because more than 8% of the population has colour vision deficiency (colour blindness).
UPPER CASE is not good for readability
Colour choice is one factor in readability. Others include using sentence case. Using upper case or capitals does not convey important messages more urgently. The image shows that using upper case to indicate a low bridge did not stop a truck driver from driving under it. Upper case is harder to read because the shape of the words are unfamiliar.
Colours for reading and learning
The processes of how we read text has an impact on how we take in information. Colour coding can help readers quickly identify key information and assist their reading and writing. Colour coding has gained popularity in classrooms to support student learning and reading.
The title of this paper is, What Color Scheme is More Effective in Assisting Readers to Locate Information in a Color-Coded Article?
From the abstract
Color coding, a technique assigning specific colors to cluster information types, has proven advantages in aiding human cognitive activities, especially reading and comprehension. The rise of Large Language Models (LLMs) has streamlined document coding, enabling simple automatic text labeling with various schemes.
This has the potential to make color-coding more accessible and benefit more users. We conducted a user study assessing various color schemes’ effectiveness in LLM-coded text documents, standardizing contrast ratios to approximately 5.55:1 across schemes. Participants performed timed information-seeking tasks in color-coded scholarly abstracts.
Results showed non-analogous and yellow-inclusive color schemes improved performance, with the latter also being more preferred by participants. These findings can inform better color scheme choices for text annotation. As LLMs advance document coding, we advocate for more research focusing on the “color” aspect of color-coding techniques.
Website readability
The most accessible websites are those that have an Easy Read option. A good example is the My Allied Health Space. At the top of the home page is the symbol for Easy Read and this is where you click to turn it on. Below is first, the standard webpage followed by the Easy Read webpage.
My Allied Health Space home page with option for Easy Read at the top of the page.
Thanks to Dr Em Bould, Senior Research Fellow at Monash University for the inspiration for this post. Dr Bould has great advice on this topic based on research.
Citizen action has never been more important and much of this is done online and through social media. This is due to the ease of technology, a pandemic and plain economics. Consequently, it’s important to make online spaces accessible for everyone. 
It is often thought that economic arguments will win the day if social justice arguments are ignored. This may be partially true if these arguments are allowed to be heard. “
The latest 
When you are in a rush it’s easy to leave out the description of the image in the alt-text box – but should you?. Alt-text is a description of an image that’s shown to people, who for some reason, can’t see the image. Among other things, alt-texts help:
Colour vision deficiency or colour blindness affects around 10 per cent of the population. But each person varies in what colours they can see, which is why it is not “colour blindness”. So what colours are best if you want all readers to enjoy colours on your website?
It’s one thing to talk about colour blindness, but it is quite another to see what it looks like to the 6-10 per cent of the population that have colour vision deficiency. 
When choosing a web developer to update your site, don’t assume they know all about accessibility. The guidelines for web accessibility are often treated like tacked on ramps to a building. That is, something you think of after you’ve done the design. To ensure accessibility of your site, it pays to know how web design decisions are made. And you don’t need to be a tech person.
The Centre for Excellence in Universal Design in Ireland has a comprehensive
The ability to access online content provides access to goods and services, and in COVID times, each other. But content on websites and smart phones is not user-friendly for everyone, particularly people with cognitive disability. However, digital communication is here to stay and it needs to be inclusive. 
