Ever seen blue creatures?
Have you discovered that there are all kinds of colors in nature, but only blue is rare?Have you ever seen blue ingredients or tigers,dogs,cats in color of blue?Even we all think that the blue sky and the ocean are not real blue.
https://www.pexels.com/photo/blue-sky-and-white-clouds-231009/
Reason
Take the example of the ocean, which is not really blue in itself. Because the sun light is roughly composed of red, orange, yellow, green, blue and purple. The light of each color has a different wavelength. When the sun shines into the sea, the light of the red, orange, yellow and green colors is easily absorbed by the water molecules. The blue and purple light is scattered. So the ocean looks like blue.
https://zh.wikipedia.org/wiki/File:Rayleigh_sunlight_scattering.png
Animals can display a variety of colors, mainly because they have pigments of various colors on their body. But for many blue animals, there is no blue pigment in it. They pass through the microstructure of their surface and interact with the light, let us think they are blue.
https://commons.wikimedia.org/wiki/File:Blue_Morpho.jpg
For this blue morpho,we zoomed in on the scales of his wings and saw some ridged surfaces like Christmas trees.It is this ridge branch that allows blue morpho to offset the light of other colors and eventually reflect only the blue light. When the light shines in, some will reflect at the top, some will penetrate inside and reflect at the bottom.But if you look at it from other angles, the butterfly you see will not be blue.
https://www.flickr.com/photos/argonne/8023114584
The animals which are real blue
In nature, animals with true blue pigments may not even be 1%.There are about 12 elusively blue animals in the world.The reason of why animals are more likely to be blue due to its own structures,Some colorists have speculated that birds and butterflies evolved to see blue a long time ago, but they have no way to evolve blue feathers. If they have blue, it means there is more way to communicate and survive between the populations. It’s much easier to change the microscopic structure of their body surface and make themselves look blue than making blue pigment genes.
