Black is a complex color with a fascinating history. While often referred to as a color, black is technically a hue that absorbs all light in the visible spectrum, reflecting none back to the eyes. The debate around whether black should be considered a color or hue comes down to definitions of these terms.
The Science of Black
Objects appear black when all visible light is absorbed rather than reflected. Unlike colors in the visible spectrum like red, yellow, or blue, black is the absence of light. Sir Isaac Newton recognized this in the 17th century when he wrote about black in his revolutionary book Opticks:
“The rays are not colored. In them there is nothing else than a certain power and disposition to stir up a sensation of this or that color. Colors in the object are nothing but dispositions to reflect this or that ray more copiously than the rest.”
Newton observed that objects that appear black absorb rays of light, rather than reflecting them to the eye. This characterization of black as the absorption of light has stood the test of modern science.
Black can result from the uniform absorption of all visible wavelengths, the combined effect of multiple pigments, or the addition of dark tints like charcoal or iron oxide. While mixing paints can create black through subtractive color mixing, this is the absence of reflected light rather than a true color.
The Color Spectrum
The visible color spectrum represents the range of electromagnetic radiation visible to the human eye. The wavelengths of visible light range from about 380 to 740 nanometers.
| Color | Wavelength range (nm) |
|---|---|
| Violet | 380-450 |
| Blue | 450-495 |
| Green | 495-570 |
| Yellow | 570-590 |
| Orange | 590-620 |
| Red | 620-750 |
Colors like red, blue, and yellow have specific wavelengths that correspond to the perception of that color in the human brain. Colors are defined by the part of the spectrum they reflect.
Black has no specific wavelength. The perception of black is caused by the uniform absorption of all visible wavelengths of light. With no wavelengths reflected back to the eyes, the brain perceives black.
Additive vs. Subtractive Color Mixing
There are two main ways that colors are created – additive and subtractive color mixing.
Additive color mixing involves the combination of light. The primary additive colors are red, green, and blue. Combining all three additive primaries results in white light. Computer and TV screens create color through additive mixing of emitted red, blue and green light.
Subtractive color mixing involves pigments and dyes. The primary subtractive colors are cyan, magenta and yellow. When paints and inks absorb certain wavelengths and reflect others, they create color through subtractive mixing. The combination of all three subtractive primaries produces black.
The creation of black pigment through subtractive color mixing demonstrates why black is considered an absence of light rather than a true color.
Properties of Black
Black has unique properties that set it apart from spectral colors:
- Black absorbs all wavelengths of visible light.
- Black combined with any other color results in a darker shade like charcoal grey or navy blue.
- Black paint is opaque, absorbing both diffuse and specular light reflection.
- Black is perceived as weighty, powerful and sophisticated.
- Black contrasts strongly with all light and bright colors.
These characteristics relate to black’s nature as an achromatic color without inherent hue or saturation. The absorption of all visible light is what places black outside the spectrum of rainbow colors.
Definitions of Color vs. Hue
The distinction between defining black as a color or hue depends on how the terms are defined.
Color is commonly defined as “the aspect of things that is caused by differing qualities of light being reflected or emitted.” This associates color with wavelength and frequency along the visible spectrum.
Hue refers more broadly to “the dominant spectral color.” Hue can encompass non-spectral colors like white, grey, and black.
Based on physical and optical properties, black is clearly a hue defined by the absence of visible wavelengths of light, rather than a distinct spectral color. Black absorbs light across the entire visible spectrum.
Cultural Meaning of Black
The meaning and symbolism of black varies cross-culturally:
- In Western cultures, black clothing is typically worn at funerals and symbolizes grief, loss, and mortality.
- In contrast, many East Asian cultures consider white to be the color of mourning and death.
- Black is associated with power, luxury, and sophistication in high fashion.
- Black has connections to villainy and evil in media and literature.
- Black represents anarchy and defiance when used by rebellious youth subcultures.
Regardless of cultural context, black retains its fundamental physical property of absorbing light. But its symbolic meaning differs dramatically based on how the color is interpreted across global cultures.
Conclusion
While called a “color,” black is technically a hue that absorbs all frequencies of visible light. It lacks distinct wavelengths and properties that define true spectral colors. The perception of black arises from the total absence of reflected light entering our eyes.
Culturally, black has rich and varied symbolic meaning. But optically, black is clearly a hue defined by the absorption of visible light rather than a distinct color within the visible spectrum.