Cows are not blue, dogs are not blue, squirrels are not blue, and will you believe if I say Blue whales are not actually blue? The animals are in various colors but if you notice animals coming in blue will be rare. When you see a blue-colored animal they look amazing, right? Nature doesn’t contain much blue and to know the reason, we should go through chemistry and physics along with evolution.
To know the reasons why the animals are not in any color, we can look at the butterflies.
Facts on blue
The brightest and the most detailed patterns are displayed by the butterflies than the other insects. These colors and the wings of the butterflies will deliver messages on its gender, the toxic, and its territory. Not all colors of butterflies are created equally, if you zoom the butterfly with a microscope, you will notice tiny scales which produce the color. And this is how the butterflies got their scientific names. Similarly, blue ring octopus glows its blue rings to show its toxicity when it is threatened.
The scales like reds, browns, oranges, and yellow contain pigment and organic molecules that absorb all colors except what we see, and all colors are absorbed by black. Animals from butterflies to birds and even humans don’t make these pigments from the beginning but it is actually made from ingredients from our diet. Flamingos are born gray in color and then later they turn pink in color. And this is because of the pigments called carotenoids in crustaceans they eat. When it comes to these colors, your pigment is based on what you eat. But this doesn’t apply to blue, as it is different.
When you move a camera, you can notice the change in color, it’s because there is no blue pigment color in butterflies.
Butterflies are blue in color but not actually blue. You might think that I am wrong but there are blue morpho butterflies and looks the prettiest. The blue color you see is not from the pigment but from the scale of the wing. Interesting right? If you zoom in, on the blue wing scale there you can see little ridges. If you look closely in the blue scale wings, you see the ridges shaped like small Christmas trees where this is the arrangement of branches giving the wings of the morpho the blue color.
When the light comes on, some light will bounce on the top surface, and other lights go in the layer and reflect on the bottom surface. Most of the colors’ wavelengths reflect from both top and bottom cancels out and that light is removed. But the blue light has the right wavelength. These reflected light waves sync and that color make it to the eye and the hall of mirrors let the blue light escape. At the base, there is a pigment that absorbs the green and red light that makes the blue even pure and this is how we get the blue color.
This happens because of the way the light bends moving from air into another material. When you fill these tiny gaps replacing the air with alcohol or other kinds of stuff, the blue disappears. Because the blue light is no longer bent the right way, the microscopic filter is broken until the alcohol evaporates and the color returns.
You might think that the butterflies will lose their color when they get wet, but these wing scales are made of naturally water-resistant material and so they stay blue in any weather. When you see through the blue jay feather, the color disappears completely no blue pigment. Light scattering microscopic beads are contained in the feather bristles but the blue light is canceled out. The highly ordered structures in the wings of the butterfly are messier like foam so instead of changing we move the colors more even from all the directions.
The feathers of the peacock tail give the color, with the shape of the feather instead of the pigment. The structure of the reflecting light is ordered like a crystal, where it exposes some certain angles brighter. Even the blue eyes you have are with the color by structures and not by pigments. Almost all the bluest living things make colors using microscopic structures with little difference in each. Nothing like reptiles, mammals, and birds make the color blue on its body and the truth is that there is only one butterfly that showed the code of making a true pigment of blue.
As a pigment, blue is really rare in nature but there is an exception that we have identified and they are the olive wings that have evolved a blue pigment and are not that common and there is no other blue pigment found.
Almost all the blue in nature is made from structures instead of pigments. Way back in time the butterflies and the other birds have evolved to see the light in blue but were not involved in a way to paint their bodies. Creating the blue pigment out of blue could require the invention of new chemistry and there is no other way to add an ingredient to the genes.
The evolution found it easier to change the shape of the bodies slightly at a microscopic level and to create a blue with physics.
Isaac newton noticed that this color is unusual and back in the 1600s, Robert hook wrote that these are fantastic and the scientists studied them because of their beauty.