The Visible Spectrum: Wavelengths and Colors

Updated on April 01, 2020

The human eye sees color over wavelengths ranging roughly from 400 nanometers (violet) to 700 nanometers (red). Low-cal from 400–700 nanometers (nm) is chosen visible light, or the visible spectrum because humans can see information technology. Light outside of this range may be visible to other organisms but cannot exist perceived by the human being eye. Colors of low-cal that correspond to narrow wavelength bands (monochromatic light) are the pure spectral colors learned using the ROYGBIV acronym: red, orange, yellow, green, blue, indigo, and violet.

Wavelengths of Visible Light

Light passing through a prism

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Some people can see further into the ultraviolet and infrared ranges than others, so the "visible calorie-free" edges of red and violet are non well-defined. Also, seeing well into 1 end of the spectrum doesn't necessarily mean you lot can see well into the other end of the spectrum. You can test yourself using a prism and a sheet of paper. Shine a vivid white light through the prism to produce a rainbow on the paper. Mark the edges and compare the size of your rainbow with that of others.

The wavelengths of visible light are:

  • Violet: 380–450 nm (688–789 THz frequency)
  • Blue: 450–495 nm
  • Greenish: 495–570 nm
  • Yellow: 570–590 nm
  • Orange: 590–620 nm
  • Ruddy: 620–750 nm (400–484 THz frequency)

Violet light has the shortest wavelength, which means information technology has the highest frequency and energy. Blood-red has the longest wavelength, the shortest frequency, and the lowest energy.

The Special Instance of Indigo

Fondo futurista

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There is no wavelength assigned to indigo. If you lot want a number, it'southward around 445 nanometers, but information technology doesn't announced on most spectra. In that location'southward a reason for this. English mathematician Isaac Newton (1643–1727) coined the word spectrum (Latin for "advent") in his 1671 book "Opticks." He divided the spectrum into vii sections—cherry, orange, yellow, light-green, blueish, indigo, and violet—in keeping with the Greek sophists, to connect the colors to days of the calendar week, musical notes, and the known objects of the solar organization.

And so, the spectrum was first described with seven colors, but most people, fifty-fifty if they meet colour well, can't actually distinguish indigo from blue or violet. The modern spectrum typically omits indigo. In fact, there is bear witness Newton's division of the spectrum doesn't even represent to the colors we ascertain by wavelengths. For example, Newton'south indigo is the modern bluish, while his blue corresponds to the color we refer to as cyan. Is your blueish the same equally my bluish? Probably, but it may non be the same equally Newton's.

Colors People Run into That Aren't on the Spectrum

Graded watercolor wash background in pink tones

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The visible spectrum does not comprehend all the colors humans perceive considering the brain also perceives unsaturated colors (e.g., pink is an unsaturated form of cherry-red) and colors that are a mixture of wavelengths (e.g., magenta). Mixing colors on a palette produces tints and hues not seen every bit spectral colors.

Colors Simply Animals Can Come across

Buckfast honey bees fly near a beehive

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Just because humans can't see beyond the visible spectrum doesn't mean animals are similarly restricted. Bees and other insects can run across ultraviolet lite, which is commonly reflected past flowers. Birds can see into the ultraviolet range (300–400 nm) and take plume visible in UV.

Humans run across further into the red range than most animals. Bees can run across color upward to near 590 nm, which is just earlier orange starts. Birds tin encounter red, just not as far toward the infrared range every bit humans.

Some people believe the goldfish is the only animal that tin can come across both infrared and ultraviolet light, but this notion is incorrect. Goldfish cannot see infrared light.