The first thing I did when I opened the article was to search for viridis. It is in there, but in a sidebar. As others have pointed out, it's weird to make such a big deal about the same sort of thinking which has been done quite well previously, and then bury it in your notes.
If you haven't already watched this, here's the SciPy2015 presentation on the development of viridis. It helps to explain the importance of color maps and how human visual color perception works.
