Colours Between RGB Primaries

RGB refers to the colours red, green and blue. These are the primary colours used by the RGB colour model to mix wavelengths of light to produce a palette of as many as 16 million colours.

Red, green and blue are the three primary colours in the RGB colour model.

In the RGB colour model green and blue are the two primary colours that together make cyan!

RGB is a colour model used to produce a full palette of colours by mixing red, green and blue light sources in different proportions.

An additive colour model explains how different coloured lights (such as LEDs or beams of light) are mixed to produce other colours.

• Additive colour refers to the methods used and effects produced by combining or mixing different wavelengths of light.
• The RGB colour model and HSB colour model are examples of additive colour models.
• Additive colour models such as the RGB colour model and HSB colour model can produce vast ranges of colours by combining red, green, and blue lights in varying proportions.
• An additive approach to colour is used to achieve precise control over the appearance of colours on digital screens of TVs, computers, and phones.

Primary colours are a set of colours from which others can be produced by mixing (pigments, dyes etc.) or overlapping (coloured lights).

• The human eye, and so human perception, is tuned to the visible spectrum and so to spectral colours between red and violet. It is the sensitivity of the eye to the electromagnetic spectrum that results in the perception of colour.
• A set of primary colours is a set of pigmented media or coloured lights that can be combined in varying amounts to produce a wide range of colours.
• This process of combining colours to produce other colours is used in applications intended to cause a human observer to experience a particular range of colours when represented by electronic displays and colour printing.
• Additive and subtractive models have been developed that predict how wavelengths of visible light, pigments and media interact.
• RGB colour is a technology used to reproduce colour in ways that match human perception.
• The primary colours used in a colour space such as CIELAB, NCS, Adobe RGB (1998) and sRGB are the result of an extensive investigation of the relationship between visible light and human colour vision.

In the field of optics, dispersion is shorthand for chromatic dispersion which refers to the way that light, under certain conditions, separates into its component wavelengths, enabling the colours corresponding with each wavelength to become visible to a human observer.

• Chromatic dispersion refers to the dispersion of light according to its wavelength or colour.
• Chromatic dispersion is the result of the relationship between wavelength and refractive index.
• When light travels from one medium (such as air) to another (such as glass or water) each wavelength is refracted differently, causing the separation of white light into its constituent colours.
• When light undergoes refraction each wavelength changes direction by a different amount. In the case of white light, the separate wavelengths fan out into distinct bands of colour with red on one side and violet on the other.
• Familiar examples of chromatic dispersion are when white light strikes a prism or raindrops and a rainbow of colours becomes visible to an observer.

RGB colour is an additive colour model in which red, green and blue light is combined to reproduce a wide range of other colours.

• The primary colours in the RGB colour model are red, green and blue.
• In the RGB model, different combinations and intensities of red, green, and blue light are mixed to create various colours. When these three colours are combined at full intensity, they produce white light.
• Additive colour models are concerned with mixing light, not dyes, inks or pigments (these rely on subtractive colour models such as the RYB colour model and the CMY colour model).
• The RGB colour model works in practice by asking three questions of any colour: how red is it (R), how green is it (G), and how blue is it (B).
• The RGB model is popular because it can easily produce a comprehensive palette of 1530 vivid hues simply by adjusting the combination and amount of each of the three primaries it contains.

The spectral colour model represents the range of pure colours that correspond to specific wavelengths of visible light. These colours are called spectral colours because they are not created by mixing other colours but are produced by a single wavelength of light. This model is important because it directly reflects how human vision perceives light that comes from natural sources, like sunlight, which contains a range of wavelengths.

• The spectral colour model is typically represented as a continuous strip, with red at one end (longest wavelength) and violet at the other (shortest wavelength).
• Wavelengths and Colour Perception: In the spectral colour model, each wavelength corresponds to a distinct colour, ranging from red (with the longest wavelength, around 700 nanometres) to violet (with the shortest wavelength, around 400 nanometres). The human eye perceives these colours as pure because they are not the result of mixing other wavelengths.
• Pure Colours: Spectral colours are considered “pure” because they are made up of only one wavelength. This is in contrast to colours produced by mixing light (like in the RGB colour model) or pigments (in the CMY model), where a combination of wavelengths leads to different colours.
• Applications: The spectral colour model is useful in understanding natural light phenomena like rainbows, where each visible colour represents a different part of the light spectrum. It is also applied in fields like optics to describe how the eye responds to light in a precise, measurable way.

ROYGBV are the initials for the sequence of colours that make up the visible spectrum: red, orange, yellow, green, blue, and violet.

• The visible spectrum refers to the range of colours visible to the human eye.
• White light, when passed through a prism, separates into a sequence of individual colours corresponding with ROYGBV which is the range of colours visible to the human eye.
• White light separates into ROYGBV because different wavelengths of light bend at slightly different angles as they enter and exit the prism.
• ROYGBV helps us remember the order of these spectral colours starting from the longest wavelength (red) to the shortest (violet).
• A rainbow spans the continuous range of spectral colours that make up the visible spectrum.
• The visible spectrum is the small band of wavelengths within the electromagnetic spectrum that corresponds with all the different colours we see in the world.
• The fact that we see the distinct bands of colour in a rainbow is an artefact of human colour vision.