The blue colour in nature is once in a blue moon thing!
Sir Issac Newton invented the simple and extremely useful colour wheel. But one of the primary colours, blue, is very shy. It rarely appears in nature! So those birds and flowers with blue colours are all just a show? Well, somewhat, yes!
Why are certain things in nature blue?
Now see. All the colours of an organism are because of the pigments they carry. So you have brown eyes because you have melanin, a pigment that is responsible for your hair and skin and, oh, even your eye colour. Plants have a pigment called anthocynin responsible for releasing a red colour.
And because of their diet, many of the animals have different colors! I mean, that is so cool! The cedar waxwing, a bird, has yellow or now red coloured wing tips because of the berries they consume. Flamingos are pink because of the pink shrimp they eat! Salmon has that orangish hue because of the orangish shellfish!
Blue pigments are hard to make. Furthermore, the organisms believed that changing your structure was easier than changing your chemical mixtures. Wait, why the structure?? Because that’s what is causing the blue colour!
The blue-morph butterfly has a striking blue colour on its wings, and if we zoom in to see the deeper structures of the wings, then they are actually in the form of ridges and roughness. The sunlight carries seven different wavelengths of color thus, when light falls on their wings, larger wavelength lights like red and orange get scattered and don’t reach the bottom ridges or the bottom surface.
This also happens because the lights like red and orange when pass from air to the wings’ medium don’t bend at the perfect angle which you guessed it right, blue light is able to. Blue light enters the medium of the wings at a perfect angle and thus reaches the bottom and ‘reflects. ‘Yes! None of the organisms that appear to be blue absorb blue light; instead, they reflect it, allowing it to reach our eyes and prompt us to exclaim, ‘There is a blue butterfly! ‘Now, because the medium is important here, if we pour alcohol on the surface of the wings, they NO LONGER PRODUCE BLUE, because the blue must pass through the alcohol to reach the wings, rather than passing through the air and entering the wings’ medium!
The peacock feathers are blue because they have crystral like structures beneath them. As a result, the blue light gets reflected easily and the structure differs slightly from each feather. Hence, there is, you see, a bit of shiny blue on one side and a high intensity of blue on the other side.
Plants’ chlorophyll absorbs blue light and cancels out the other colors, resulting in blue leaves. But blue light isn’t of good quality, hence bad quality light isn’t helpful for plant growth and thus chlorophyll then reflects green light!
Thus, all organisms have no blue pigments but different structures to take in and reflect blue light and we think it is their colour! Isn’t it true now to say, ‘Everything is an illusion?’
Finally, there is only one organism in the entire world that can produce blue pigment, and that is the Obrina Olivewing butterfly.
To summarise, the blue colour in nature is once in a blue moon thing, because making blue pigment is difficult and organisms change their structures such that they reflect blue light. So they just tricked us!