Jump to content
Science Forums

Psa For The Colorblind


JMJones0424

Recommended Posts

This article contains an excellent example of a useless, to me, heatmap.  Somewhere around 10% of humans are colorblind.  There is no reason that heatmaps such as this one cannot be made so that colorblind people can interpret them.  This is a particularly egregious example, but I run across this problem frequently.  Make your heatmaps more colorful!  To me, both of the extremes look exactly the same and the relative gradation on either side of zero to five is indistinguishable.

 

 

hsiang1HR-800x423.jpg

Link to comment
Share on other sites

Make your heatmaps more colorful is a bad request, especially since my complaint is that I don't see color the same way that others do.  Instead, I should have said that the gradation of values in heatmaps should not rely solely upon different hues that a significant minority of the population are not able to distinguish in the same way that the majority does.  If the above heat map had been constructed with the zero to five color as the low end of the spectrum and the 25 to 28 color as the high end of the spectrum, I would be able to interpret it.  Instead, it appears to me that both 25 to 28 and -13 to -10 are represented by the same color.  This is clearly not a good way to represent data to those that see colors the way I do.

 

I am red-green colorblind.  I can distinguish between the colors that we commonly call red and green, but I am not able to see such a significant difference between these colors as those that are not deficient in this area.  As such, when color hues rely solely upon the amount of either red or green, such as that of green or brown, or that of purple and blue, I have a hard time distinguishing between them.

 

In heatmaps like the example shown above, there is no logical reason that the colors chosen should have been used.  This map uses only nine variables to display information, however I can only distinctly identify five.  As such, for me, this map is useless.  Had the creators used a different strategy for conveying their information, the map would be more valuable to me.

 

A quick google search has led me to many different sites that discuss ways to ensure that the vast majority of those that can see will be able to interpret your data.  All I ask is that if you create a heatmap to display information, consider the fact that not all people see colors the same way that you do.

 

https://www.tableau.com/about/blog/2016/4/examining-data-viz-rules-dont-use-red-green-together-53463

http://www.somersault1824.com/tips-for-designing-scientific-figures-for-color-blind-readers/

 

The TL;DR version is this: don't use colors in a heatmap where the hue of red or green is the sole determining factor for interpretation of your values.  A quick and easy test is to convert your image to grey-scale.  If your data becomes meaningless in grey-scale, then it may be hard to interpret by those that don't see colors the same way that you do.

Edited by JMJones0424
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
×
×
  • Create New...