Traffic lights for everyone
Stephen Westland of Colour chat recently posted about a clever new LED traffic light developed in Japan. Here’s my tweet with the link to Westland’s original blog post:
I really like the idea of making a traffic light that works for everyone: for people with full color vision and people with color vision deficiencies. In fact, I think we should do the same with our color palettes. Why do I say that?
A rainbow for everyone
Take a look at Figure 1 below. This is a map of the Bouguer Gravity (terrain corrected Bouguer Gravity to be precise) in Southern Tuscany, colored using a rainbow palette. I intentianally left out the colorbar. For a moment ignore the sharp gradient changes at the yellow and cyan color (that is one of the topics of my upcoming series “The rainbow is dead…long live the rainbow!”). Can you tell which color is representing high values an which low? If you have used a mnemonic like ROY B GIV and can tell that highs are towards the Southwest and lows towards the Northeast, then you are right and you also have full color vision, just like me. Great, because this post is exacly for us, the “normals”.
Take now a look at Figure 2: