The question of whether white and black are “colors” depends on the scientific perspective. While everyday understanding groups them with hues like red or blue, the physics of light and human perception offer a more nuanced explanation. This understanding clarifies the unique roles white and black play in the spectrum of perceived color.
What is Color?
Color is our brain’s interpretation of different wavelengths of electromagnetic radiation. Only a small segment of the electromagnetic spectrum is visible to the human eye, known as the visible light spectrum, spanning approximately 380 to 750 nanometers. Our eyes contain specialized cells called cones, which detect these wavelengths and transmit signals to the brain. Humans possess three types of cone cells, each sensitive to different ranges of wavelengths: red, green, and blue light. The brain processes these combined signals to create our perception of millions of distinct colors.
The Science of White
An object appears white when it reflects nearly all wavelengths of visible light that strike its surface, scattering or reflecting all component wavelengths equally back to our eyes. White light, such as sunlight, is a combination of all colors within the visible spectrum. From a physics standpoint, white is considered a combination of all colors of light, rather than a single color.
The Science of Black
In contrast, black is observed when an object absorbs nearly all visible wavelengths of light that fall upon it. This absorption converts the light energy into other forms, often heat. Black is described as the absence of reflected light. While no object perfectly absorbs 100% of light, materials like Vantablack can absorb over 99.9% of incident light.
Color Mixing and Perception
The perception of white and black is understood through different types of color mixing. Additive color mixing involves combining light sources. The primary colors of light are red, green, and blue; when combined in equal proportions, they produce white light. This principle is utilized in devices like television screens and computer monitors, which generate images by emitting varying intensities of red, green, and blue light.
Conversely, subtractive color mixing pertains to pigments, dyes, or inks, where colors are created by absorbing specific wavelengths of light. The primary colors for pigments are cyan, magenta, and yellow. When these three primary pigments are mixed, they absorb a wide range of wavelengths, resulting in black or a very dark brown.