In the September 16th issue of Science, a fascinating article called Sunlight affects whether languages have a word for ‘blue’ called to mind how best to describe the color of the oceans, lakes, and seas.
Depending on the time of day, amount of sunshine, and latitude, the color of the ocean can range from navy blue and royal blue to azure and electric blue to turquoise. Depending on the depth and clarity of the venue, water can be also described from emerald green and forest green to sea green and kelly green.
Even with the same body of water throughout the day and night, the descriptors of the water color can change. I can sit on a balcony in a hotel in Waikiki Beach on Oahu or Santorini Island in Greece or Ishigaki Island in Okinawa and the color will change throughout the day as the sun rises in the morning and then sets in the evening where a darkness merges to a light green to turquoise to a brilliant blue, and then reverts back to darkness.
Cathleen O’Grady, PhD writes in Science, “Languages treat this spectrum in different ways: Some have separate words for green and blue, others lump the two together. Dan Dediu, an evolutionary linguist at Lumière University Lyon 2 have found that people with more exposure to sunlight are more likely to speak languages that lump green and blue together, under a term that linguists dub “grue.” That’s because of the effects of a lifetime of light exposure, the team speculates: Lots of Sun causes a condition called “lens brunescence” that makes it harder to distinguish the two hues.
“Light exposure played a big role in whether languages separate blue from green, the researchers conclude this week in Scientific Reports. In brighter places (either those that were closer to the equator or had less annual cloud cover) such as Central America and East Africa, languages were significantly less likely to separate “green” from “blue.” That suggests a lifetime of exposure to bright light pushes whole communities away from baking a blue-green distinction into their language.”
In Central America and East Africa, languages are significantly less likely to separate green from blue. [But] living near a lake increased the chance of having a separate word for blue.“


Sunlight affects whether languages have a word for ‘blue’ © 2021 American Association for the Advancement of Science