Choose colour scales carefully

When designing scientific graphics, one key choice is about which colour scale to use (something discussed in several previous posts). The animated graphic below is a simulation of how an image would look to someone who is colour blind (a few percent of men).

Watch how the pattern emerges as the level of simulated colour blindness is reduced:

Simple conclusion: try to avoid using shades of red and green in the same figure to maximise the accessibility of your graphics. Sadly, some scientific journals are still publishing figures which are impossible to read for those who are colour blind. Join the campaign!

[Similar Ishihara images are often used to test for colour blindness. Thanks to Doug McNeall for useful comments on an earlier version of the graphic.]

2 thoughts on “Choose colour scales carefully

  1. I am very disappointed by the tendency to lose annotated isotherm lines, isobar lines, etc. from charts, relying solely on coloured charts and a colour scale key.

    There is little or nothing wrong with my colour vision but I cannot carry the colour from the chart and arrive at the scale with that colour accurately recalled.

    If people would simply put the iso- lines back in, even with annotation, one little task in life would be so much easier.

    I am not sure why this is happening, but then I don’t think there was anything wrong with synoptic charts for weather forecasting. So what do I know!

    I also object to apparent condescension that amusing me with pretty colours is all I am good for.

Leave a Reply

Your email address will not be published. Required fields are marked *