Why is the use of colour and good contrast important?
Considering colour and contrast in your digital content is important for many reasons:
- there are approximately 3 million colour blind people in Britain, approximately 4.5% of our population
- colours on a screen can seem less vibrant in the sunshine and may not be readable if there is too little contrast between foreground and background
- colours, contrast, resolution and size can vary between screen and projectors
- tired eyes have to work harder when colour contrast is poor, this can lead to eye-strain and headaches
- the amount of light that reaches the back of the eye reduces as a natural part of ageing
If your document has a high level of contrast between text and background, more people can see and use the content in a variety of situations.
People who are blind, have low vision, or are colour-blind might miss out on the meaning conveyed by colours alone so it is important to use other distinguishing factors too.
How to do it
You need to ensure that colour is not the only means of conveying information
For example, you may have a graph using two different colours for positive and negative information. However someone's vision condition might mean they may not be able to decipher the two colours and therefore may not be able to distinguish or interpret the information using colour alone. You should also label the content.
A good tip is to imagine your content being printed in black and white, is it still understandable without the need for seeing colours?
Use sufficient contrast for text and background colours
When creating any content make sure you consider whether there is sufficient contrast between foreground text and the background.
SCULPT by Helen Wilson is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License. Based on work at Worcestershire County Council.