It is well-known that color words appear in languages in a particular order. We’ll discuss one of the landmark papers that established this fact: Color-term evolution and order (1969). If you are interested in a more up-to-date study see Key et al. (1999).
After spending about an hour discussing color terms and language we’ll (start to) make our own cyanometers (this activity was suggested by David Cohen). A cyanometer is a collection of different blue color chips (usually arranged in a circle) which can be used to ‘quantify’ the color of the sky. It was instrumental in developing a physical answer to the (literally) age-old question: “why is the sky blue?” If you are interested in the history of the answers to this question see the History of explanations of the blueness of the sky .