The proper term for color depends on the context. From a technical perspective, color can be defined as the visual perceptual property corresponding to the categories called color names. More simply stated, color is the attribute of visual perception consisting of any combination of chromatic and achromatic content. This means color is what the eye sees and the brain interprets as having hue, saturation and brightness.
How Do We Perceive Color?
Human color perception is a complex process that starts with light and ends with the brain interpreting signals from photoreceptor cells in the eyes. Here is a brief overview of the color perception process:
- Light sources emit wavelengths of electromagnetic radiation called visible light.
- When visible light hits an object, some wavelengths are absorbed while others are reflected.
- The reflected light enters the eye through the cornea and pupil.
- In the retina, photoreceptor cells called cones respond to different wavelengths of light.
- Cone cells trigger nerve impulses that travel to the visual cortex in the brain.
- The brain interprets signals from cone cells as color.
There are three types of cone cells, each responding maximally to different wavelengths corresponding to red, green and blue light. The combination of signals from all three cone types enables us to perceive the full spectrum of visible colors.
Color Terminology
There are many technical terms used to describe color characteristics and phenomena. Here are some of the main ones:
| Term | Definition |
| Hue | The attribute of color perception denoted by color names like red, orange, yellow, green, etc. |
| Saturation | The intensity of hue in a color; how pure or grayed a color is. |
| Brightness | The perceived amount of light emitted or reflected by a color. |
| Shade | A hue mixed with black to make it darker. |
| Tint | A hue mixed with white to make it lighter. |
| Primary colors | Colors that can be mixed to create all other hues; traditionally red, yellow and blue. |
In additive color systems like RGB (red, green, blue), primary colors refer to the light sources that are combined to produce a range of colors. In subtractive systems like CMYK (cyan, magenta, yellow, black), primaries are the pigments or dyes that absorb some wavelengths and reflect others.
Color Models and Spaces
To describe colors numerically, various color models and spaces have been developed. Some important examples include:
- RGB: An additive model based on mixing red, green and blue light. Used for computer displays, TVs, image sensors, etc.
- CMYK: A subtractive model based on mixing cyan, magenta, yellow and black pigments. Used for color printing.
- YIQ: A color space used in analog NTSC TV broadcasting.
- LAB: Device-independent model based on human perception, with L for lightness, A for green/red axis, and B for blue/yellow.
- HSV: Model describing colors by hue, saturation and value/brightness.
- Pantone: Standardized color reproduction system for printing/design specified by numbered formulas.
These color models allow colors to be quantified, calibrated and communicated accurately. Conversion between models is done through color management systems and profiles.
Color Theory
Color theory is a body of principles defining relationships between colors and how they are perceived. It provides guidance on mixing colors and combining them aesthetically in art, design and other areas. Some key concepts include:
- Color wheel: Arrangement of hues in a circle to show relationships.
- Color harmony: Pleasing color combinations created through schemes like analogous, complementary and split-complementary.
- Color context: How surrounding colors influence the perception of a color.
- Color symbolism: Associations of colors with concepts, moods, etc. in culture.
- Color psychology: Emotional and behavioral effects of color perception.
Modern color theory originated with Isaac Newton and Johann Wolfgang von Goethe. It was subsequently advanced by artists and scientists including J.M.W. Turner, Ogden Rood and Albert Munsell. Today color theory principles are widely applied in art, fashion and design.
Color Deficiencies
There are various medical conditions that affect color perception. The main ones include:
| Condition | Description |
| Color blindness | Inability to distinguish certain colors, usually reds and greens. |
| Monochromacy | Complete lack of color vision; only able to see in shades of grey. |
| Dichromacy | Impaired color vision with only two functioning cone types. |
| Anomalous trichromacy | Deficient color perception in three cone types. |
Color vision deficiencies are usually inherited genetic conditions. The most common form is red-green color blindness, which affects around 1 in 12 men and 1 in 200 women globally. This makes colors hard to distinguish in the red-yellow-green range.
Color in Nature
Color plays a major role in the natural world and evolution. Here are some key examples:
- Plants have green chlorophyll to absorb light for photosynthesis.
- Flowering plants have colored pigments to attract pollinators.
- Many fruits and vegetables have bright colors to stand out.
- Some animal colorations are for camouflage while others warn predators.
- Birds and fish often have bright colors for mating displays.
- Skin pigments protect against UV radiation and aid vitamin D production.
Studying the functions and evolution of color in nature provides insights into biology, ecology and environmental adaptation. Engineered color applications like bio-inspired photonics also draw on nature’s ingenuity.
Industrial Color Use
Color is ubiquitous in industrial processes and commercial products. Some examples include:
- Dyes and pigments: Used in textiles, plastics, paints, inks, cosmetics and other areas.
- Food coloring: Adds color lost in processing or improves natural shades.
- Colorimeters: Measure and specify colors in quality control and manufacturing.
- Color coding: Visual identification system for wires, industrial fluids, warnings, etc.
- Display technologies: Advanced materials and processes to produce digital displays, signage, etc.
Effective and economical coloration is vital for consumer appeal and commercial success in today’s visually oriented markets. This drives constant innovation and sophisticated use of color in industry.
Color and Culture
Color is intricately linked to culture, with significant social, religious and symbolic associations. Some examples include:
- Mourning colors like black in some cultures and white in others.
- Red evokes different emotions in China, India and Western cultures.
- Gold and purple signify royalty and privilege in European history.
- Green is associated with Islam, prosperity in China, and ecology movements.
- Saffron invocation in Hinduism, the orange of Buddhism robes.
- Rainbow Pride flag representing LGBTQ communities worldwide.
These associations often have deep historical and regional significance. Marketers must consider cultural color symbolism carefully when tailoring products and campaigns to local markets.
Color Trends and Forecasting
Fashion and design industries rely heavily on predicting popular colors in upcoming seasons. This color forecasting involves:
- Evaluating upcoming social-economic trends, consumer psychology, etc.
- Analyzing past and present color popularity and cycles.
- Researching upcoming color introductions by textile/paint suppliers.
- Consulting with fashion designers, color professionals and trend forecasters.
- Publishing color trend reports for designers and manufacturers.
Major forecasting firms include Pantone, Coloro and Trend Union. Their predictions drive development of new color palettes and product ranges in fashion, cosmetics, interior design and other industries.
Conclusion
Color is a complex phenomenon that draws on fields from physics to neuroscience to culture. But for most of us, it is simply the familiar property that makes our world beautiful, expressive and filled with meaning. Understanding the technical side of color helps us use it more creatively and effectively in art, design and visualization to bring color’s magic to others.
