Color is a complex phenomenon that involves physics, physiology, and psychology. The same color can appear different to different people based on differences in their vision and perception. There are several factors that influence how we see color:
The Physics of Color
Physically, color is light of different wavelengths. When light hits an object, some wavelengths are absorbed while others are reflected. The reflected wavelengths determine the color we see. For example, a tomato appears red because it absorbs most wavelengths of light except red.
The visible spectrum of light that humans can see ranges from about 400-700 nanometers (nm). Violet light has the shortest wavelength while red has the longest. The wavelength of light determines its hue.
Anatomy of the Eye
The anatomy and physiology of our eyes also affect how we perceive color. Light enters through the cornea and pupil and is focused by the lens onto the retina. The retina contains photoreceptor cells called rods and cones.
Rods enable vision in low light. Cones are responsible for color vision. There are three types of cones that each respond best to different wavelengths of light. Cone cells contain pigments that absorb light of short (S/blue), medium (M/green), or long (L/red) wavelengths . The ratio of excitation between the three cone types allows us to distinguish millions of colors.
Age and Color Vision
As we age, the lenses in our eyes gradually yellow, filtering out some blue light. The number of photoreceptors also declines. These age-related changes make it more difficult to distinguish colors, especially blues .
|Age Group||Color Vision Ability|
|Infants||Can only see black, white and grays|
|Young children||Color vision similar to adults|
|Adults under 60||Peak color vision ability|
|Adults over 60||Difficulty distinguishing blues and purples|
About 1 in 12 men and 1 in 200 women have some form of color vision deficiency or color blindness . This makes it difficult or impossible to distinguish certain shades.
The most common type is red-green color blindness where people have difficulty distinguishing between red and green. This is caused by missing or faulty cone cells. Other types include blue-yellow color blindness and complete color blindness.
Genetics influence the number and distribution of cone photoreceptors in our retinas, impacting color perception. For example, women may have a fourth type of cone that can detect more shades of red .
Small genetic variations mean we each have a unique assortment of cone cells. This causes people to perceive color slightly differently. However, these differences are subtle and do not affect normal color vision and discrimination abilities.
Our brains interpret the signals from photoreceptors to produce our subjective visual experience of color. This process involves complex neural pathways and visual processing centers.
Cone cells adapt to ambient light conditions. The brain compensates so colors appear consistent despite changes in illumination. This auto-adjustment can cause variations in how people perceive color.
Culture, language, and past experiences may also influence how our brains interpret color. The Himba tribe in Namibia, for instance, has difficulty distinguishing between blue and green but sees more shades of green than English speakers .
Optical illusions reveal the subjective nature of color perception. In this checkerboard illusion, the A and B squares are exactly the same shade of gray:
Our visual system is tricked and the two grays appear very different. This shows how color appearance can change based on surrounding context.
The type of light illuminating an object impacts how its color is perceived. Colors appear most vibrant in full sunlight. As light dims at dusk, color vision declines due to rod cells taking over from cones.
Indoor lighting also alters color appearance. Standard bulbs have spiky spectral emission compared to sunlight. Fluorescent lighting emits spiky blue and orange wavelengths. This makes assessing product colors under store lighting challenging.
No two displays reproduce color exactly the same way. Factors like display technology, brightness, contrast, viewing angle, and factory calibration all affect color presentation.
An image that looks red on your laptop may seem more orange on a friend’s phone. Side-by-side, the variance is obvious. Companies like Pantone provide standardized color profiles to help align colors across devices.
Certain medical conditions affect color vision. Cataracts cause the lens to become cloudy, leading to muted and yellowed color perception. Diabetes can impair color discrimination, especially between blues and greens.
Some medications also impact color vision. Digoxin, used to treat heart conditions, can make white objects appear yellow . Antibiotics like ciprofloxacin may also cause color vision abnormalities.
Psychology and Perception
Human color perception is subjective, complex, and influenced by psychological factors. while physics defines color physically and physiology limits our vision anatomically, psychology shapes how color is actually perceived.
Color constancy allows objects to appear the same color under different lighting conditions by factoring in contextual cues like shadows . Familiarity also gives consistent color to known objects like grass, bananas, and the sky.
Cognitive biases can skew color perception. Confirmation bias may cause someone to perceive an object’s color differently to support existing beliefs. Selective attention may make someone notice warm tones more under certain circumstances.
Mood, emotions, and memories may also tint our color experience. Synesthesia can blend color perception with sounds, words, or scents, associating specific hues with things like music or letters.
Many complex factors shape our individual experience of color. While physics defines the physical properties of light and physiology limits color vision, psychology plays a key role in how we each perceive the world of color. Subtle anatomical differences, age, genes, gender, culture, language, and cognitive biases all contribute to the incredible diversity of color perception between people.
So while we can define colors scientifically, our lived experience of them depends on the unique configuration and quirks of our visual systems and brains. This explains why color is both physical and personal – a phenomenon that fascinates precisely because it differs for everyone who sees it.