The color spectrum, wavelength and color temperature
In 1664, while still a student, Sir Isaac Newton investigated the refraction of light by a glass prism. Developing over a few years a series of increasingly elaborate, refined, and exact experiments, Newton discovered measurable, mathematical patterns in the phenomenon of colour. He found white light to be a mixture of infinitely varied coloured rays (manifest in the rainbow and the spectrum), each ray definable by the angle through which it is refracted on entering or leaving a given transparent medium.
Color spectrum in a rainbow.
Sir Isaac Newton discovered that ordinary white light consists of an infinite amount of colors; the colors in a rainbow.
Color spectrum of white light falling through a prism.
The electromagnetic spectrum also contains the cosmic rays, gamma rays, x-rays, ultra violet, shortwave infrared, infrared, radio waves and electromagnetic waves:
Build-up of the electromagnetic Spectrum.
The Commission Internationale de l’Eclairage (CIE), internationally better known as International Commission on Illumination, is the international authority in the field of light, lightsources, color and colorspace. The CIE has its headquarters in Vienna, Austria. The CIE works together with the ISO orginisation and is seen by ISO as a standardization group.
The CIE 1931 color space chromaticity diagram with wavelengths in nanometers, developed in 1931, is still used today as the standard to define colors, and as a reference for other color spaces. The figure is a two-dimensional display of colors with the same intensity (brightness), according to the standard-CIE-1931-perception that is based on observations of color measurements by humans. A complete display of colors is actually three-dimensional, where the z-axis displays the brightness.
The CIE 1931 color space chromaticity diagram with wavelengths in nanometers.
The three-dimensional image looks like a pyramid. This color space cannot be used to show the difference between the colors. That’s why this system was further developed to the CIELAB-system.
The official CIE chromaticity diagram is calculated by the Techno Team Ledtuning to the RGB color space (see the CIE diagram above). It is in color rendering a reasonable estimation to the real CIE standard.
From the 1931 CIE diagram, we have the wavelength of each color (for every 0.1 nm) also calculated to RGB color space and indicated the specific wavelength at every 5 nm.
Color spectrum, precision perception of color and the corresponding wavelength.
The color yellow that only has one spectral component at 580nm is created on a monitor by using additive color mixing of the colors red and green. These two colors each have their own spectral component at 645nm and 510 nm. Because both wavelengths and light production may vary between monitors the “white balance” should be set correctly.
From the 1931 CIE diagram, we also calculated color temperature to RGB color space and indicated these color temperatures with the matching colors on the screen.
700nm deep red - LED: some types, low brightness
680nm pure red - LED: ultra red, hyper red, deep red
660nm pure red - LED: ultra red, hyper red, deep red
645nm bright red - LED: 640-650nm
640nm bright red
635nm ’HeNe laser’ orange-red - LED: super red: 635nm
630nm ’HeNe laser’ orange-red - LED: HE red: 625-630nm
625nm orange-red - LED: HE red: 625-630nm
620nm clear orange-red
615nm reddish orange - LED: 615-617nm
610nm pure orange - LED: 609-610-612nm
605nm orange - LED: 605nm
600nm amber-orange - LED: 600nm
595nm amber (warm yellow, yellow-orange)
592nm amber (warm yellow, yellow-orange) - LED: 590-592-595nm
590nm Natrium yellow
585nm yellow - LED: HE Yellow,
580nm pure yellow - LED: HE Yellow,
575nm lemon yellow, become a little greenish
570nm yellowish green (between yellow and green)
565nm yellowgreen - LED: early types
560nm yellowgreen - LED: pure green, 562nm
555nm yellowish lime green
550nm yellowish emerald green
545nm emerald green
540nm emerald green
535nm pure emerald green
530nm pure emerald green
525nm pure green
520nm pure green
510nm greenish turquoise (RGB pure green)
505nm greenishe blue / turquoise
500nm greenishe cyan
495nm turquoisish, a little sky-blue
490nm turquoisish, light sky-blue
485nm bright, a little azure-blue - LED: 480-485-488nm
480nm bright, a little azure-blue
475nm bright, a little greenish azure-blue
470nm bright blue with a liitle greenishe emphasis
465nm bright blue with a liitle greenishe emphasis
460nm bright blue
455nm bright blue
450nm pure blue - LED: Royal Blue
445nm diep blue / violet-blue
440nm diep blue / violet-blue
435nm diep blue / violet-blue
430nm violettish blue - LED: 626-428-430nm
425nm violettish blue - LED: 626-428-430nm
420nm deep violettish blue
410nm violet with bluish emphasis
405nm pure violet
400nm deep and more twilight color violet than 405nm
395nm deep royal purple
390nm deep royal purple with reddish tint
385nm twilight purple with deep red blur
380nm almost no longer visible purple