Is color a property of matter or is it created in the brain?

Colors are both real and fictional. Light consists of different wavelengths of light. Our eyes can perceive these different wavelengths and they correspond to a 'color'. Therefore, a wavelength of 400 nanometers appears purple, while 700 nanometers appears red. However, the 100 nanometer wavelength, which falls into the ultraviolet range, is invisible to us - although bees can see it!

If asked to imagine a banana, most of us can picture a yellow fruit with a characteristic elongated shape. The idea of ​​a transparent, orange or purple banana is unlikely to ever cross the mind of the vast majority of people. Color contributes significantly to how we perceive and imagine things, enriching our visual experience and imparting meaning to the world around us, but what exactly is color? ?

Think about the "yellow" color on the banana you envisioned. Is this yellow color an intrinsic quality of the banana, located inside the peel as a fundamental and inherent attribute of the banana? Or is it a cognitive structure formed by the complex workings of our brains? These questions are at the heart of the debate about what color really is, whether it's a physical or chemical aspect of things, or whether it's something the brain creates.

The emitted wavelengths then travel to our eyes, helping us perceive color.

What is color and how do we see it?

Color is defined as an intrinsic physical property of matter. When light hits the surface of an object, the object absorbs certain wavelengths and reflects others. The emitted wavelengths then travel to our eyes, helping us perceive color.

Humans can only see wavelengths between 400-700 nanometers, what we call the visual spectrum or visible spectrum. This is a small part of the vast electromagnetic spectrum, which includes radio waves, microwaves, infrared radiation, visible light, ultraviolet rays, X-rays and gamma rays. A wavelength of 700 nanometers appears red, while one of 400 nanometers appears purple, but a wavelength of 100 nanometers is invisible to us.

The wavelength reflected from the surface of an object determines the color of that object.

Physiologically, the retina is located at the back of the eye, detecting light. It contains photoreceptor cells called rods, which respond to low or dim light, and cones, which respond to brighter conditions. These cells respond to different wavelengths of light, sending signals to the brain through the optic nerve. The signal is first relayed to the hippocampus and then to the visual cortex, where color information is merged with other visual data, such as shape and motion, culminating in a pattern. comprehensive photo.

At first glance, this scientific explanation confirms the assertion that color is a property of matter and not a product of the brain's imagination.

But is this really true?

If color is an inherent property of matter, then why do we have disagreements about the color of objects? As the famous saying goes, "My red is not your red - My red is not your red".

Same object but makes people see different colors

In 2015, a social media post about a wedding dress sparked fierce debate about its color. While some people are adamant that the dress is blue and black, which happens to be the actual color of the dress, others claim it is yellow and white.

This is also a curious question for scientists, who wonder why different people's brains trick them differently about the color of their dress.

The dress caused a stir because no one agreed on its color.

Vision scientists propose that differences in color perception stem from differences in interpreting the lighting conditions surrounding the dress. Color perception is easily altered by environmental light.

Normally, the brain adjusts to these changes to ensure consistent color perception, a phenomenon known as color constancy.

However, the brain's ability to regulate may be impaired. And that's what creates the optical illusion. 

The role of the brain and illumination

David Williams, Allyn professor of Medical Optics and director of the Center for Visual Sciences, provided some insight to explain what might be going on in the case of the dress. He suggests that because the photo of the dress lacks complete information about lighting conditions, some viewers may perceive it as brightly lit, while others may see it as less bright.

When asked about differences in assumptions about the illumination of light between different people, Williams speculated that it could be due to differences in how different people's brains work.

Different species have different numbers and distributions of photoreceptors.

How animals see color

Different species have different numbers and distributions of photoreceptors, which is influenced by their habitat. For example, fish that live in shallow, sunny waters tend to have more cone cells than fish in deeper water.

Differences in photoreceptor number, distribution, and sensitivity can lead to diverse color perception. For example, dogs only have two types of cone cells so they have dichromatic vision, unlike trichromatic humans. This makes them less sensitive to red and green colors. Therefore, a red object may appear brown or gray to a dog.

Some animals can detect wavelengths beyond our visible spectrum. Bees can see UV rays, along with blue and green colors. For bees, flowers are not just pretty pink or bright yellow.