How many colours do you need to visualise data scored on a five-point scale?
Two.

If you went with the obvious answer of five colours, here’s what you get:
The green and grey figure wins in two ways. First, it tells a story: about a third of respondents view Wikipedia favourably. (Although there are other interpretations of the data shown, a good figure emphasises a single message.) Second, the grey and green version just looks better.
Continue reading “Grey and one other colour: a foolproof colour scheme for scientists”