Blue is, besides green, the most frequent color we see in daily life. It is the color we see when we look at the sky and sea, yet it is still very difficult to find in nature. There are very few things in nature that are actually blue.
Science is telling us that what we see as the sky is light coming through layers of the atmosphere, and even though we perceive it as blue, it has no actual color pigment. Sea, on the other hand, is often seen as blue, and this happens because of the reflecting nature of the water - and what water reflects the most is the sky.
The tendency for blue to appear in animal pigment is super rare. Plants can produce blue pigment because of anthocyanins, while animals usually do not have chemical compounds to color them blue. The phenomena of some animals being blue comes from some structural effects such as selective reflection - which doesn't make them have blue pigment, only that we are able to see them as blue.
For example, blue jay, a bird which produces so much melanin that it should be black, yet because the air sacks among it's feathers captures light, the bird looks blue to the human eye. Even though these species are super rare, there are a few examples of blue in animals such as moon jellyfish, blue butterfly, peacock and blue eyed cats.
Among human beings, blue eyes are much more rare than brown, which makes them popular. Although, here it is also the case that there is no blue pigment, only melanin which determines the color of the iris depending on the amount of it's presence. Also, it is interesting that humans can be born with blue eyes and then while they're growing up and producing more melanin, this color changes throughout lifetime.
Melanin is produced in the iris to protect the eye from UV radiation and high-energy light. This is why, however beautiful, blue eyes are much more sensitive to daily light than any other eyes.
Blue is one of the primary colors, so we cannot create it by mixing other colors. Blue pigments are made from minerals, which are crushed and ground into powder and then turned to paint. Even though it doesn't naturally appear as a pigment in living creatures, it still is one of the most popular colors in visual art, fashion, interior design and it awakes inspiration among us every day.
About the author
Nina Petrov is an activist, poet, performer and mathematician. She communicates with the world mostly through words, movement and equations, but sometimes also by speaking very loudly. The only truth she could say about herself is that she keeps changing every day, never stops learning and interacting with her surroundings.