Daniel Lewis goes bird watching, and bird watchers need to know their colors. Lewis is also an historian, so he got interested in how color terms came to be standardized.
The work of another bird-watcher was decisive: “Other important color dictionaries were published at the start of the 20th century when [Robert] Ridgway published his work—some of them strange and wonderful. The French Society of Chrysanthemists, for instance, created a two-volume set of swatches and names in 1905 for their own botanical uses. Holly Green was described as ‘the ordinary color of the foliage of the common holly, viewed from 1 to 2 meters away, and without considering reflections.’ And despite the fact that the work was meant for international consumption, its soul remained French. Sky Blue, for example, was described as ‘the color reminiscent of pure sky, in summer (in the climate of Paris).’