Have you ever wondered if the sky appears the same shade of blue to everyone who looks up? Or pondered whether your neighbor's perfect avocado green is your idea of a traffic light green? Color shapes our reality. It influences our choices, affects our moods, and even alters our perceptions. But how does color perception work?
The Subjectivity of Color Perception
The perception of color is an intricate process. Understanding how we perceive colors can help explain why different people might see the same color differently, and how this affects their interaction with the world. Here’s a deeper look into the biological, psychological, and environmental factors contributing to color perception.
Biological Factors
The biological basis of color perception begins with the structure and function of the human eye, particularly the retina, which contains photoreceptors that respond to light. Here are the key theories that describe the biological aspects:
Trichromatic Theory:
developed by Thomas Young and Hermann von Helmholtz, the Trichromatic Theory explains that the human eye contains three types of receptors (cones) each sensitive to one of three colors: red, green, and blue [1]. These colors are the basic building blocks of our color vision.
According to this theory, by mixing these three colors in different intensities, we can see a wide range of colors. However, small differences in these cones among individuals can affect how we see colors. For example, one person's "vivid red" might be another's "slightly dull red" based purely on minor differences in these cone cells. This theory primarily deals with how our eyes detect light, which is the first step in how we perceive colors.
Opponent Process Theory:
Ewald Hering proposed the Opponent Process Theory, which complements the Trichromatic Theory. This theory explains that our ability to see colors involves different systems in our brains: one system handles redand green colors, another manages blue and yellow, and a third one deals with black and white [2]. The theory states that we can't see certain combinations of colors, like red-green or blue-yellow, at the same time because our brains are wired to block out these combinations. Essentially, this theory helps us understand how our brain takes in signals from the eyes and turns them into the colors we see
Psychological and Environmental Factors
While biological theories explain how light is transformed into visual signals, psychological and environmental factors delve into how these signals are interpreted and can affect behaviors and emotions:
Color constancy:
Color constancy ensures that the color of objects looks relatively similar under varying lighting conditions [3]. This means our brain adjusts colors so they appear consistent, helping us feel stable in our surroundings.
For example, it allows us to recognize that a red apple is red whether it’s seen in the dim light of dusk or the bright light of noon. However, the colors around an object and the lighting can sometimes fool our brains into seeing colors differently — a classic example being the infamous "dress" that appeared blue and black to some and white and gold to others.
Emotional and cultural effects:
Colors can also evoke certain emotional responses and carry cultural meanings, which can alter our perception of them.
For example, in many Western societies, white is often associated with purity and weddings, black with mourning and formality, red with love and danger, and green with luck and freshness. In contrast, white may be associated with mourning and funerals in countries like China and India.
Red is typically seen as a lucky color in China, used in festivals and weddings to bring good fortune and happiness. Green is particularly significant in many Middle Eastern countries, where it symbolizes Islam and is considered sacred.
Contextual effects:
Historical events and social contexts also shape how colors are perceived and used. For example, past uses of color in national flags, political movements, or significant cultural events can make long-lasting associations that influence a society’s interpretation of color.
The Experience of Color Blindness
Color blindness, or color vision deficiency, adds another layer to the complexity of color perception. This condition arises from the absence or malfunctioning of one or more types of cone cells in the retina, affecting approximately 1 in 12 men and 1 in 200 women globally [4].
The most common form of color blindness is the difficulty in distinguishing red and green shades.
People with color blindness often develop unique systems for identifying colors based on context clues and brightness levels.
They might use context clues, such as the known colors of common objects, or rely on variations in brightness to differentiate hues.
For example, someone who struggles to tell the difference between red and green might know that grass is typically green and will use this information to guide their understanding of colors in a scene. Similarly, traffic lights present a common context where the position of lights can assist in color identification—red is usually at the top or left, while green is at the bottom or right.
Brightness levels also play a significant role.
Those with color blindness might not see the color of a flower accurately, but they can perceive whether it's lighter or darker than the surrounding foliage, using this gradient as a clue to its possible color.
These adaptive strategies highlight the adaptability and resourcefulness of the human sensory system. Despite the absence or malfunction of certain receptors in the eye, the brain finds alternative ways to interpret and understand visual information.
This capacity for adaptation not only aids in daily functioning but also enriches the experiences of those with color vision deficiencies by allowing them to interact with the world in visually meaningful ways.
Implications for Design and Accessibility
Understanding the variability in color perception among individuals is essential, particularly in fields like design and accessibility. This awareness is critical because designers must create products, services, and environments that are inclusive and usable for everyone, including those with color vision deficiencies.
For designers working in digital media, such as website and app development, it's vital to consider how color choices can affect usability. Colors often convey specific actions or feelings; for example, red commonly indicates a warning or error, while green might suggest success or confirmation. However, for someone with color blindness, these signals could be indistinguishable. To address this, designers must incorporate additional cues, such as text labels, icons, or different patterns, ensuring that information is accessible to all users, regardless of how they perceive color.
In physical environments, such as interior design or urban planning, similar principles apply. Public spaces, signage, and emergency systems must be designed to accommodate those with color vision deficiencies. This might mean using contrasting textures or shapes to differentiate elements traditionally marked by color alone. For example, tactile paving is a method used on sidewalks and subway platforms to guide individuals with visual impairments, including those who cannot rely on color cues.
By incorporating these strategies, we can ensure that environments, products, and services cater to the diverse needs of the population, acknowledging and respecting the broad spectrum of human sensory experiences.
Color perception is a deeply personal and complex experience, influenced by a blend of biological, psychological, and cultural factors. Recognizing the subjective nature of color and the differences in how it is perceived can lead to greater empathy and inclusivity in how we design our world. Whether it’s by accommodating color blindness in visual designs or appreciating the subtle differences in individual color experiences, expanding our understanding of color perception enriches our appreciation of the world around us.
Sources:
Lee B. B. (2008). The evolution of concepts of color vision. Neurociencias, 4(4), 209–224.
Pridmore RW. Single cell spectrally opposed responses: Opponent colors or complementary colors?. J Optics. 2012;42(1):8-18. doi:10.1007/s12596-012-0090-0
Gert, J. (2017). Color constancy. Oxford Scholarship Online.
About colour blindness. (2022, April 27). Colour Blind Awareness. https://www.colourblindawareness.org/colour-blindness/
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