We explain what the visible spectrum of light is, its wavelength range and the colors that make it up. Also, what is light.

What is the visible spectrum?
The visible spectrum or visible light is the region of the electromagnetic spectrum that the human eye is capable of perceiving and translate into the different colors we know.
Electromagnetic radiation has different frequencies, of which our eye is able to perceive only a segment: the corresponding to wavelengths between 380 and 750 nanometers approximately. Depending on the person, this range may be slightly wider or slightly narrower.
In white light, the visible spectrum contains absolutely all the colors that we are capable of seeing human beings, depending on the wavelength of the radiation. A rainbow, for example, is the result of a phenomenon of light refraction thanks to the water in the atmosphere, which alters its speed and “decomposes” it into different colors.
This means that, depending on the properties of light waves (specifically their wavelengths), we can talk about the different colors, as follows:
- Red (rubeus in Latin). Between 780 and 618 nanometers.
- Orange (aureus). Between 618 and 581 nanometers.
- Yellow (flavius). Between 581 and 570 nanometers.
- Green (viridis). Between 570 and 497 nanometers.
- Cyan (coeruleus). Between 497 and 476 nanometers.
- Blue (indicus). Between 476 and 427 nanometers.
- Violet (violaceus). Between 427 and 380 nanometers.
Many known tones and colors cannot be seen in the decomposition of the visible spectrum because they are not monochromatic, that is, they involve the combination of two or more wavelengths: pink or pink, for example, is understood as a red mixed with white. The same occurs for known colors such as brown, silver, magenta and gold.
Similarly, Black and white, more than colors, are understood as values of light saturation: white corresponds to the sum of all colors, that is, to full light; while black corresponds to the absence of light.
Outside the visible spectrum are radiation with the wavelengths of infrared light (above approximately 750 nm) and ultraviolet light (below approximately 400 nm), both extremes already invisible to the eye. human. Other life forms, such as insects, are capable of perceiving these wavelengths. We humans can only do this with the help of optical instruments and devices of our invention.
Continue with: Color theory
References
- “Visible spectrum” on Wikipedia.
- “Introduction to light” at Khan Academy.
- “Visible spectrum” in e-ducativa (Spain).
- “Visible spectrum of light” (video) at the University of Illinois (USA).
- “The visible spectrum” in The Encyclopaedia Britannica.