The picture of the strawberries below is a well known optical illusion. Our brains perceive the picture as being under a blue light source, so automatically remove the blue components of the colour. This means we see the strawberries as red. But what happens if we zoom in on a 'red' section of strawberry? Click the image to take a closer look.
[Click image to zoom]
Look at the colour scheme in the chart below. You may instinctively feel that it is generally lacking in taste... but there are actually more fundamental problems with the choice of colour here.
Red-green colour blindness affects about 1 in 12 men and 1 in 200 women.
To ensure that most people can distinguish between the colours you choose, it is best to vary their lightness/luminance. Blue is generally considered a good first colour choice, since blues remain largely unchanged for most types of colour blindness.
Can you find the Ls and Is among all the Ts?
Are you sure you got them all? You probably did, as we've made this fairly easy. But it might have taken a few seconds to be sure.
We can make it easier for users to understand differences in data with sparing and sensible use of colour.
Only use different colours when they represent helpful differences in the data.
In this chart, there is no meaning to the colour - the creator of the chart just thought it looked nice. The colours are a distraction from the real message in the data and can actually make it harder to get our key messages across.
Some colours are associated with particular meaning.
E.g. Green is for good and red is for bad.
The colours in this chart are quite jarring as they go against our natural association between colour and fruit. Using unexpected colours to represent familiar concepts slows down information processing and forces the reader to work harder. Where possible, use colours that users would expect to see to represent familiar concepts.
If you have more than a handful of lines, it becomes difficult for viewers to quickly distinguish between the different colours. As a creator, you need to design your charts carefully to help the reader quickly understand what the data is telling them.