Color is a biological “hallucination” created by Paṭicca Samuppāda to serve as the essential scaffolding for human survival. We will examine the difficulties encountered when seeing only in gray (black, white, and gray). Human life would be impossible if we could not perceive at least those colors.
February 6, 2026; #13 and #14 revised 2/7/2026
Color Is a ‘Biological Hallucination’
1. As modern science calls it, color is a biological ‘hallucination,’ agreeing with the Buddha, who called it a ‘mirage.’ Objects in the world do not have colors, and light is not colored either, as I summarized in the previous post, “Rūpa Samudaya – A ‘Colorful World’ Is Created by the Mind.”
- Yet humans would not be able to live their lives if external objects did not appear in color. A colorless existence would disrupt human life and would make life impossible.
- If we were to suddenly lose the ability to perceive a wide variety of colors (but still able to see in ‘black and white’)—a condition known as total achromatopsia—even that would affect the structural integrity of human society, and safety and economy would face immediate destabilization.
- The following video summarizes our discussion in “Rūpa Samudaya – A ‘Colorful World’ Is Created by the Mind” and leads into a discussion of a ‘black and white’ or ‘gray’ world.
Anomalies in Human Vision
2. All our sensory inputs arrive in the brain via chemical and electrical signals. According to scientists (like the presenter of the above video), this amazing organ, weighing only about 1.2 kg (2.6 pounds), can convert those signals not only into the correct shapes and sizes of objects but also ‘add colors’ that help us live our lives.
- @ 5:50 mins: The fact that each of us experiences the world a little bit differently is confirmed by the variation in ‘color perception.’ (There are much larger variations in animals; some see more colors than us and some only see in ‘black and white’).
- @7:50 mins: Most humans have three types of sensors (called ‘cones’) that can detect red, green, and blue. When two or all three sensors detect light, those ‘mixtures’ can provide the sensation of thousands of ‘colors.’ For example, one sees yellow when both red and green sensors are triggered simultaneously. Some people can see only a few colors; they are called ‘color blind.’
- @12 mins: The discussion on the ‘dress’ confirms the variations in color perception among the people in the audience.
- @13 mins: Most people assume that things in the world have colors. However, neither things in the world nor light has color. It is an amazing fact that ‘color’ does not exist in the world. Scientists say it is ‘made up’ by the brain, but they cannot explain how an inert brain can conjure up such an amazing feat. (Note: The same holds for the idea that thoughts arise in the brain; scientists cannot explain it, and it is called the ‘hard problem of consciousness’).
- @15:45 mins: He shows the wavelengths of electromagnetic radiation, ranging from radio waves (used in radios) to X-rays (used in X-ray machines). The visible part of electromagnetic radiation is a tiny portion in that range from 400 to 700 nanometers. (Sunlight is strong in that tiny range, and that is why nature — Paṭicca Samuppāda — ‘chose that range’ for assigning ‘colors’ as we will discuss later).
- @18.50 mins: Therefore, ‘color’ is an illusion, but it keeps us alive.
Two Types of Sensors in Our Eyes – Cones and Rods
3. There are two types of sensors in our eyes: Cones and rods (cone-shaped and rod-shaped sensors).
- A multitude of colors are assigned using three types of ‘cone sensors.‘ Each one is triggered within a range of wavelengths, as shown in the picture below. ‘Blue cones’ are triggered if the wavelength is roughly in the 400-500 nm range (labelled ‘S’), but maximized at 420 nm; ‘green cones’ are triggered optimally at 530 nm (range approximately 450-640 nm; labelled ‘M’), and ‘red cones’ at 565 nm (range approximately 470-670 nm; labelled ‘L’). That allows ‘mixing of colors’, leading to even millions of hues.
- The ‘rod sensors‘ interpret light only in gray, and no other colors like red or green; the wavelength range is roughly 400 to 600 nm. Under low-light conditions (like in a dark room or after sunset), ‘cone sensors‘ do not function, and we see only in shades of gray with the ‘rod sensors.’
Achromatopsia – Seeing in Gray (No Other Colors)
4. For about 1 in 30,000 people, ‘cone sensors’ are absent in their eyes. Thus, they can see only in gray. Furthermore, they experience acute discomfort in bright light. They have a condition called ‘achromatopsia.’
- Some others can see only a few colors, and they are said to have ‘color blindness.’ This is also another form of ‘achromatopsia.’ Such deficiencies are due to ‘kamma vipāka.’
- The following video explains ‘achromatopsia’ a bit further.
- You could skip the technical details from 4:00 to 5:15. From 5:15 to 5:45, the video explains the two forms of ‘achromatopsia’ mentioned above. You can also skip the rest of the video, unless you are interested in technical details.
Further Details
5. The following video explains some intermediate steps between our sensory organs and the brain and how the ‘perception’ of sight, smell, and sound arises.
- It provides a simple explanation of how signals are transmitted to various parts of the brain.
- Of course, it does not explain how the perception of sights, smells, and sounds are generated.
- @13:30 mins: He says perception arises, but how those electrical signals are converted to ‘mental impressions’ cannot be explained in modern science. We will discuss that in terms of Paṭicca Samuppāda in upcoming posts.
Now, let us look at some implications for our lives if the world is seen only in black, white, and gray.
The Collapse of Universal Safety Systems
6. Humanity has engineered its environment using color as the primary language for urgent communication. This is not arbitrary; the brain processes color faster than it processes shapes or text. In a colorless world, the “Red/Yellow/Green” paradigm of global transit would fail.
- General: Emergency exits glow green, fire extinguishers stand out in red, and medical supplies like bandages or defibrillators use color for quick identification during crises. A world without these distinctions would amplify errors, delays, and fatalities, as the brain’s rapid processing of color (faster than shape or text) is lost. Factually, color enhances visual search efficiency by up to 40% in cluttered environments, making it indispensable for urban survival.
-
Traffic and Aviation: A traffic light becomes a series of identical gray orbs. While one could argue we would learn to look at the “position” of the light (top vs. bottom), the margin for error increases exponentially in low-visibility conditions like fog or rain, where the chromatic “glow” is the only detectable signal.
-
Industrial Safety: Warning signs and hazard labels universally employ color codes: red for danger, yellow for caution, and orange for construction zones. High-voltage wires, gas canisters, and chemical valves are color-coded by international ISO standards. A “Yellow” pipe denotes flammable fluids; a “Red” button denotes an emergency stop. Without these visual shortcuts, every human interaction with industrial machinery would require a cognitive “reading” of labels, slowing down reaction times in life-or-death scenarios.
The Failure of Nutritional Identification
7. Whether in a supermarket or a forest, humans rely on reflectance curves to judge the chemical composition of matter.
- Ripeness: Color acts as an immediate indicator of quality, safety, and nutritional value in daily sustenance. Humans rely on visual cues to assess ripeness: bananas turning yellow signal edibility, while strawberries redden to indicate peak sweetness and nutrient content.
-
Toxicity: Without color, distinguishing fresh produce from spoiled would require alternative senses, such as smell or texture, which are slower and less reliable in supermarkets or kitchens. Mold on bread might appear as mere shadows, and overripe fruits could blend indistinguishably with their surroundings, increasing the risk of foodborne illness. More critically, in many fungi and flora, the difference between “edible” and “lethal” is signaled by subtle shifts in hue. Without color, the human diet would become a “gambling” experience unless every piece of food was chemically tested.
-
The Economy of Agriculture: The global food supply chain relies on color-sorting technology and human inspectors to identify blight, mold, and rot. A gray-scale world would mask the “browning” of meat or the “graying” of bread, leading to mass foodborne illness.
Medical Diagnostics and Physiological Monitoring
8. The human body uses color as its primary “dashboard” for health.
-
Dermatology and Oxygenation: Doctors diagnose cyanosis (lack of oxygen) by the blue tint of the lips or fingertips. Jaundice is characterized by yellowing of the sclera (the white part of the eye). Rashes, infections, and inflammations are signaled by “redness” (erythema).
-
Diagnostic Tools: Skin tones reveal jaundice (yellowing) or cyanosis (a bluish tint indicating oxygen deprivation), while urine color charts in clinics detect dehydration or infection. Many medical tests, such as pH strips, urine analysis, and certain lateral flow assays (like pregnancy or COVID tests), rely on color changes to communicate results. Without color, these simple, low-cost tools would be useless, necessitating complex electronic sensors for even the most basic health checks.
-
Pharmaceutical pills are color-coded to prevent mix-ups—blue for sedatives, white for painkillers—reducing medication errors that cause thousands of deaths annually.
The Architecture of Information and Technology
9. We live in the era of the “Pixel.” Human interface design is built on the premise that the brain can categorize information via color.
-
Data Visualization: Graphs, maps, and spreadsheets use color to differentiate variables. A topographical map uses color to show altitude; a weather map uses it to show storm intensity. In a gray-scale world, a “Heat Map” of a viral outbreak or a financial market collapse would be an illegible smear of gray.
-
Electronics: The wiring of the modern world is a rainbow. An electrician identifies the “hot” wire vs. the “ground” wire by color. In a colorless world, maintaining the electrical grid or a computer motherboard would become nearly impossible without labeling every millimeter of wire.
Education and Other Areas
10. In education, color-coded notes and diagrams improve retention; studies show students recall information 20-30% better when presented in color versus black-and-white.
-
Maps and infographics rely on color to differentiate regions, data sets, or routes—think subway lines in varied hues for quick orientation. Without this, comprehension slows, errors rise, and collaborative efforts falter.
- In sports, team uniforms in distinct colors aid identification, reducing confusion in fast-paced games.
- On a psychological level, color profoundly impacts mood, cognition, and well-being, making its absence a barrier to mental health. A sunset or a flower garden would lose its appeal.
However, human life in a truly ‘colorless world’ would be impossible. Let’s discuss that now.
What If We Cannot See in Any Color?
11. We discussed the difficulties faced with only ‘gray vision’ in #6 through #10 above. However, Gray, white, and black are also colors. Those are also part of the ‘illusion of sight.’
- If we truly remove the “colorizing” scheme (i.e., kāma saññā), even those discussed above would not be there; we get nothing.
- We can compare the lives described in #6 through #10 above to a black-and-white movie; in a truly colorless world, there would be no movie!
- Most of us cannot even imagine a world without any colors. It would not be a world filled with ‘blackness,’ because black is also a color. We simply will not see anything. Of course, everything will still exist in the world, with the Sun still emitting electromagnetic radiation; yet, there will be no ‘light’ to see anything in the absence of ‘color perception.’
- This is the most astonishing thing that I realized a few years ago. I almost fell out of my chair. We take it for granted to see ‘sunlight’ every morning. Can we even imagine life without ‘sunrise’? And not even ‘moonlight’? Not even blackness? All those are ‘false saññā‘ that are generated in the mind! This is why the Buddha taught that all rūpa (those we experience) are of anicca nature; they are illusions!
- Yet, it is a necessary illusion for us to live our lives. As we have discussed, a living Arahant would still have the ‘color perception’ (and taste, and other perceptions too, i.e., kāma saññā); see #9 of “Origin of Attachment – Rāga Triggered by Saññā.” Otherwise, they would essentially become blind at the moment of Arahant-phala. They only lose ‘kāma rāga‘ and not ‘kāma saññā.’ Anyone born human (even the Buddha) will have ‘kāma saññā‘ built into them.
Blind Do Not See ‘Black’
12. Many people think that the blind see only black. However, those who are blind simply do not experience sight; black is also a color.
- I can provide my personal experience. I had all sensory faculties working until 2019, when I underwent brain surgery to remove a benign tumor in my brain. However, during that operation, the nerves that transmit signals from my nose to the brain got cut. Now I smell nothing at all. That sensory faculty is missing for me.
- The following video describes the experience of a woman who was born blind.
13. Note that she had “never seen anything” in her life. It seems that either her physical eyes or the optic nerve/visual cortex in the brain had been damaged at birth. Apparently, the cakkhu pasāda rūpa (in her gandhabba) was fully functional. That is why she could see after her gandhabba popped out of her body. (She came out of the physical body with her manomaya kāya or her gandhabba; that is what an Out-of-Body Experience means.)
- However, in other cases, one may be born blind because one may not be born with the cakkhu pasāda rūpa. In that case, even if the gandhabba comes out of the body, it would not be able to see because of the absence of the cakkhu pasāda rūpa.
- All five sensory faculties (where ‘perception’ occurs) are in the gandhabba or the manōmaya kāya. While the gandhabba is trapped inside the physical body, the brain must process signals from the eyes, ears, nose, tongue, and body before sending them to the corresponding pasāda rūpa. Then that pasāda rūpa transfers the signal to the hadaya vatthu, and it is the hadaya vatthu that really “sees,” “hears,” etc. See “Brain – Interface between Mind and Body.”
- The above video is from the post “Gandhabba in a Human Body – an Analogy.” It is one of a series of relevant posts in “Brain and the Gandhabba.”
What if We Lose All ‘Sensory Illusions’
14. As discussed above, without the ‘illusion of color,’ we will completely lose the ‘visual sensory faculty,’ i.e., there will be nothing to see!
- We have discussed the fact that music, tasty foods, smell, or touch are also ‘illusory perceptions’; see “The Illusion of Perception (Saññā) – It Is Scientific Consensus.“
- That means we would lose all sensory faculties. Human life would not be possible!
- Therefore, we must learn to live within the ‘mundane reality‘ based on kāma saññā.
- Yet, suffering in the cycle of rebirth cannot be ended until we comprehend the ‘ultimate reality,’ i.e., all our perceptions (kāma saññā) are illusions. We engage in akusala kamma (that sustain the rebirth process) based on such illusions. See the summary below in #17.
Feynman Came Close to Figuring It Out
15. Richard Feynman, a Nobel prize winner and one of the best physicists, understood that the mind does not reside in the brain, as he explains in the following videos. Yet, he had no explanation. If he had heard the Buddha’s detailed explanation of the mental body (overlapping the physical heart while it is inside the physical body), he would have understood.
- @19:30 mins: Feynman says he believes consciousness to be fundamental, not derived from matter. He got it! But unfortunately, he was not aware of Buddha’s teachings, at least not the correct ones. Buddha’s teachings also explain how matter arises via the mind: “Manōpubbangamā dhammā..“
- @24:10 mins: He describes a thought experiment where a copy of a person is re-made atom by atom exactly. We can understand why the ‘copy’ will not work, because the ‘gandhabba‘ (mental body) has much more than a few atoms. The information associated with the gandhabba (its access to the viññāṇa dhātu, for example) cannot be copied! See “Memory Recall for Gandhabba in a Human Body” for the explanation of how the gandhabba receives memories from the ‘viññāṇa dhātu.’ All relevant posts on that are in “Brain and the Gandhabba.” That discussion reveals the depth of Buddha’s true teachings!
- The ‘binding problem’ Dr. Feynman revealed is also resolved with the gandhabba. It all happens in the mind (with its access to viññāṇa dhātu), and not in the brain.
- @27:30 mins: The ‘viewer’ is gandhabba!
- @33 mins, Feynman asks: Why does consciousness matter? Here is the answer from the Buddha: Because we suffer in the cycle of rebirth. Actually, we suffer due to ‘defiled consciousness.’ Once we purify the consciousness, suffering ends. Why does the consciousness automatically get defiled? Because of the automatic attachment to the kāma saññā, i.e., the ‘illusions (such as color, taste, etc.) created by the mind itself.’ Once this is understood, everything becomes crystal clear.
16. Here is another video by Dr. Feynman. Both these videos are recent, and I am glad I found them in time for this post. If only he came across the teachings of the Buddha! He would have understood.
- @13:45 mins: He says, ‘The brain starts preparing actions milliseconds before you become aware of them.’ That is the ‘purāna kamma‘ stage; see #17 below. Even though most people just ‘go with the flow’ (i.e., succumb to the temptations arising in the ‘purāna kamma‘ stage), we can control the ‘nava kamma‘ stage. His description holds for animals, who just ‘go with the flow’ without the ability to think. What he says from @15.40 mins onward is correct.
- Professor Feynman passed away in 1988. May he be reborn in an environment where he will come across the true teachings of the Buddha!
Summary
17. As discussed in the previous post, “Rūpa Samudaya – A ‘Colorful World’ Is Created by the Mind,” a colorful world is an illusion generated by the mind. All types of enticing rūpa (sights, sounds, tastes, smells, touches) arise in the mind due to ‘illusions’ created via saññā (see “The Illusion of Perception (Saññā) – It Is Scientific Consensus”); that is why all rūpa are of ‘anicca nature.’ That is a key insight. This is the ‘ultimate reality.’
- On the other hand, as we discussed in this post, that illusion is necessary for us to live our lives. That is the ‘mundane reality‘ we must cope with. We cannot ignore it, because then we cannot live our lives.
- We must balance those two realities and work to stop attaching to the kāma saññā by fully comprehending the ‘mind contamination process’ that happens in two stages: ‘purāna kamma‘ and ‘nava kamma.‘ Note that the ‘purāna kamma‘ stage starts automatically (without our conscious awareness) via kāma saññā in our kāma loka. That is why it is critical to understand the role of saññā in the ‘mind contamination process.’
- Cultivation of wisdom (paññā) based on such an effort will first lead to the breaking of the first three diṭṭhi saṁyojana by comprehending the process. Then, the breaking of the kāma rāga saṁyojana is accomplished by the cultivation of Satipaṭṭhāna, which will lead to the Anāgāmi stage; thus, we cannot remove the kāma saññā built into our bodies, but we can stop attaching to it by eliminating the kāma rāga saṁyojana. Breaking of any saṁyojana can be achieved only by cultivating wisdom (paññā) by following the Noble Eightfold Path.