Q: Is it true that Rainbows look different to different people?
Krishna:
Image source: IStock
Human beings just assume things. They think the world they see look the same to others around too. They think the colours they see, pictures and things they view, are the same for everyone.
Which of course is a delusion!
Individual human beings see and interpret different things in the same surroundings because perception is an active construction of the brain, not a simple video recording. When two people look at the exact same scene, their physical hardware, gaze patterns, life experiences, and cultural backgrounds cause their minds to filter and make meaning of the information differently.
The things that affect a human vision and perception
1. Biological and Physical differences
Eye anatomy and physiology: The hardware of vision varies. People differ in the health of their corneas and lenses, the density of light-sensitive rods and cones on the retina, and genetic variations in colour sensitivity—such as colour blindness, standard trichromacy (seeing 1–10 million colours), or rare genetic tetrachromacy (seeing hundreds of millions of more colours).
Early neural processing: Eye-tracking and brain-imaging studies show that selective visual attention boosts electrical signals for parts of a scene while actively weakening or filtering out others within milliseconds of light hitting the retina.
2. Where we look (gaze patterns)
Fixation habits: Eye-tracking research reveals that people direct their gazes differently depending on what catches their interest. For instance, when viewing everyday images, the percentage of time people fixate on faces versus background details can vary more than twofold among individuals.
Cultural scanning: Cultural background trains where we look. Studies show that Westerners tend to focus heavily on central focal points like a person's eyes and mouth, while East Asians often distribute their gaze more broadly across the nose and background context.
3. Psychology, memory, and expectation
Past experiences and history: The brain relies on past events, memories, and personal history to decode what light entering the eye actually means. If you have a specific fear, fondness, or expertise (such as a mechanic noticing a loose bolt versus a casual passerby), your brain elevates that detail to the foreground.
Expectations and goals: What you need or expect to see in a moment changes your visual threshold. If you are looking for a lost red jacket in a crowded room, your brain tunes itself to pop red hues out from the noise.
Emotions and context: Current emotional states, stress, and the surrounding social or physical environment shift how the brain assigns emotional weight and narrative meaning to a visual scene.
Therefore, what you see before you need not be the same as your friend beside you views!
So yes, your rainbow is not my rainbow!
The rainbow you see is yours alone! Your brother standing next to you is perceiving a totally different rainbow of his, formed by different raindrops and positioned differently in the sky.
Rainbows are technically different and crafted specifically for each individual by Nature!
No two people see the exact same rainbow because a rainbow is not a physical, tangible object hanging in the sky; it is a personal optical illusion created specifically for your eyes.
Why rainbows are personal
Optical illusion: A rainbow is not a physical object hanging in the sky; it is an optical phenomenon. It only exists as light enters your specific eyes.
The magic angle: Sunlight bends and reflects off raindrops at very precise angles (about 42 degrees for red light and 40 degrees for violet).
Different angles and droplets: Because you are standing in a unique spot, the light entering your eyes is bouncing off a completely different set of raindrops than the light entering someone else's eyes standing next to you. If you take a step to the side, the rainbow shifts with you because a new set of raindrops catches the light.
The commonly observed feature of the rainbow is that when the sun is near the horizon, the nearly vertical arcs of the rainbow near the ground are often brighter than the upper part of the arc.
Drop size can make a considerable difference to the intensity and colour of the rainbow.
Even your own eyes differ: Your left eye and your right eye are a few centimetres apart, meaning they are looking through slightly different drops and seeing two slightly distinct rainbows that your brain seamlessly fuses together.
Biology and perception: Biological differences in how your eyes' cone cells perceive light and how your brain interprets colour mean that even if two people could theoretically look at the exact same light rays, their internal perception of the shades would still vary.
I have seen people fighting over colours, descriptions, images, shapes, physical features and several other things.
This is completely in vain because you can never truly convince a person who perceives the world differently to yours to accept your view of the world!
I am pretty sure now you totally agree with me because I have just shown you how to eye the world exactly like I do!
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I want to tell you another interesting thing
If I ask you, ''How many colours can you see in a rainbow?", your immediate answer would be "seven".
Now if I tease you with a "Really?"
Your reply would be, "Yes, Red, Orange, Yellow, Green, Blue, Indigo, and Violet." Because that is what you studied in school.
But a rainbow is not made of a fixed number of distinct stripes. Scientifically, it is a continuous spectrum of light containing an infinite number of smoothly blending shades and wavelengths.
Where did the number of colours come from?
It is Sir Isaac Newton’s choice! In the 17th century, Newton originally divided the light spectrum into five colurs (red, yellow, green, blue, and violet). He later added orange and indigo to make seven colours, matching the seven notes of a musical scale and symbolic numbers in ancient philosophy.
Is indigo real? Indigo is widely considered an arbitrary addition rather than a physically distinct band. Most modern scientists and colour theorists note that indigo simply blends into blue and violet without a clear physical boundary.
Cultural and biological perceptions make people put the distinct number! Whether people see six, seven, or any other number of bands depends on human eye biology, brain processing, and language conventions rather than a strict rule of physics.
The original discoverer of the spectrum of visible light — Sir Isaac Newton — thought that Indigo was one of the spectral colours. But of note is that Cyan is missing from Newton’s scale. Today, it is more common to give “Cyan” to the colour that Newton thought was “Blue”, and “Blue” to the colour that Newton thought was “Indigo”.
Sir Isaac Newton famously included indigo in his seven-colour spectrum, but omitted cyan.
Historians and optical scientists generally agree with this observation. Newton's original colour choices do not perfectly align with modern colour definitions for two reasons:
The Shift in Labels: What Newton called "Blue" actually refers to the greenish-blue we now call Cyan, and what he called "Indigo" refers to the deep, pure blue on modern displays.
The "Seven" Colour Bias: Newton believed that the universe operated on harmonic, mathematical ratios. Because there are seven notes in a musical scale, he was determined to identify seven distinct colours in the spectrum to create a cosmic symmetry. To make the numbers fit, he explicitly added orange and indigo as distinct "semitones" between the primary colours.
If we translated Newton’s 1672 spectrum into modern English colour terms, the traditional ROYGBIV sequence changes significantly:
| Newton's 17th-Century Label |
Modern Colour Equivalent |
|---|
| Red |
Red |
| Orange |
Orange |
| Yellow |
Yellow |
| Green |
Green |
| Blue |
Cyan / Sky Blue |
| Indigo |
True Blue / Indigo |
| Violet |
Violet |
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