As with all OnColor™ color management software, OnColor™ QC Lite interfaces with most color measurement instruments in the market today. It offers a common GUI (Graphical User Interface) and data format for those with multiple brands of color measurement instruments that have been relegated in the past to use instrument manufacturers. Lite definition is - light. How to use lite in a sentence. Colorlite manufactures lenses with a special coating which are designed to enhance a person's color vision. The color blind glasses will work with each type of red-green color vision deficiencies, including the most severe types of Protanopy (total lack of red cones) and Deuteranopy (total lack of green cones). One of the darker light-gray hues on our list, Analytical Gray by Sherwin-Williams is a favorite of Valente's because it's an almost greige shade with soft green undertones. 'It’s easy to pair this paint color with either warm grays or tans in your furniture and accessories,' she says.

A monochromic^[1] image is composed of one color (or values of one color).^[2] The term monochrome comes from the Ancient Greek: μονόχρωμος, romanized: monochromos, lit.'having one color'.

A monochromatic object or image reflects colors in shades of limited colors or hues. Images using only shades of grey (with or without black or white) are called grayscale or black-and-white. However, scientifically speaking, monochromatic light refers to visible light of a narrow band of wavelengths (see spectral color).

Application[edit]

Of an image, the term monochrome is usually taken to mean the same as black and white or, more likely, grayscale, but may also be used to refer to other combinations containing only tones of a single color, such as green-and-white or green-and-red. It may also refer to sepia displaying tones from light tan to dark brown or cyanotype ('blueprint') images, and early photographic methods such as daguerreotypes, ambrotypes, and tintypes, each of which may be used to produce a monochromatic image.

In computing, monochrome has two meanings:

• it may mean having only one color which is either on or off (also known as a binary image),
• allowing shades of that color.

A monochrome computer display is able to display only a single color, often green, amber, red or white, and often also shades of that color.

In film photography, monochrome is typically the use of black-and-white film.Originally, all photography was done in monochrome. Although color photography was possible even in the late 19th century, easily used color films, such as Kodachrome, were not available until the mid-1930s.

In digital photography, monochrome is the capture of only shades of black by the sensor, or by post-processing a color image to present only the perceived brightness by combining the values of multiple channels (usually red, blue, and green). The weighting of individual channels may be selected to achieve a desired artistic effect; if only the red channel is selected by the weighting then the effect will be similar to that of using a red filter on panchromatic film. If the red channel is eliminated and the green and blue combined then the effect will be similar to that of orthochromatic film or the use of a cyan filter on panchromatic film. The selection of weighting thus allows a wide range of artistic expression in the final monochromatic image.

For production of an anaglyph image the original color stereogram source may first be reduced to monochrome in order to simplify the rendering of the image. This is sometimes required in cases where a color image would render in a confusing manner given the colors and patterns present in the source image and the selection filters used (typically red and its complement, cyan).^[3]

In physics[edit]

In physics, monochromatic light is electromagnetic radiation of a single frequency. In the context of physics, no source of electromagnetic radiation is purely monochromatic, since that would require a wave of infinite duration as a consequence of the Fourier transform's localization property (cf. spectral coherence). Even very controlled sources such as lasers operate in a range of frequencies (known as the spectral linewidth). In practice, filtered light, diffraction grating separated light and laser light are all routinely referred to as monochromatic. Often light sources can be compared and one be labeled as “more monochromatic” (in a similar usage as monodispersity). A device which isolates a narrow band of frequencies from a broader-bandwidth source is called a monochromator, even though the bandwidth is often explicitly specified, and thus a collection of frequencies is understood.

See also[edit]

• Duotone – the use of two ink colors in printing
• Halftone – the use of black and white in a pattern that is perceived as shades of grey (may be extended also to color images)
• Polychrome – of multiple colors, the opposite of monochrome
• Monochromacy (color blindness)
• Selective color – use of monochrome and color selectively within an image
• Monochrome painting – monochromes in art

References[edit]

1. ^From the Ancient Greek: μονόχρωμος – monochromos “having one color”.
2. ^'monochrome', Merriam-Webster Online Dictionary, 2009, retrieved October 16, 2009
3. ^'Monochromatic'. Dictionary.com Unabridged. Random House, Inc. Retrieved March 23, 2013.

Light is made up of wavelengths of light, and each wavelength is a particular colour. The colour we see is a result of which wavelengths are reflected back to our eyes.

Visible light

Visible light is the small part within the electromagnetic spectrum that human eyes are sensitive to and can detect.

Visible light waves consist of different wavelengths. The colour of visible light depends on its wavelength. These wavelengths range from 700 nm at the red end of the spectrum to 400 nm at the violet end.

White light is actually made of all of the colours of the rainbow because it contains all wavelengths, and it is described as polychromatic light. Light from a torch or the Sun is a good example of this.

Light from a laser is monochromatic, which means it only produces one colour. (Lasers are extremely dangerous and can cause permanent eye damage. Extreme care must be taken to ensure that light from a laser never enters someone’s eyes.)

Colour of objects

Objects appear different colours because they absorb some colours (wavelengths) and reflected or transmit other colours. The colours we see are the wavelengths that are reflected or transmitted.

For example, a red shirt looks red because the dye molecules in the fabric have absorbed the wavelengths of light from the violet/blue end of the spectrum. Red light is the only light that is reflected from the shirt. If only blue light is shone onto a red shirt, the shirt would appear black, because the blue would be absorbed and there would be no red light to be reflected.

White objects appear white because they reflect all colours. Black objects absorb all colours so no light is reflected.

Colour detection

The retina of our eyes contains two types of photoreceptors – rods and cones. The cones detect colour. The rods only let us see things in black, white and grey. Our cones only work when the light is bright enough, but not when light is very dim. This is why things look grey and we cannot see colours at night when the light is dim.

There are three types of cones in the human eye that are sensitive to short (S), medium (M) and long (L) wavelengths of light in the visible spectrum. (These cones have traditionally been known as blue-sensitive, green-sensitive and red-sensitive, but as each cone is actually responsive to a range of wavelengths, the S, M and L labels are more accepted now.)

These three types of colour receptor allow the brain to perceive signals from the retina as different colours. Some estimate that humans are able to distinguish about 10 million colours.

Mixing colours

The primary colours of light are red, green and blue. Mixing these colours in different proportions can make all the colours of the light we see. This is how TV and computer screens work. If you look at a screen with a magnifying glass you will be able to see that only these three colours are being used. For example, red and green lights are used to make our brain perceive the image as yellow.

When coloured lights are mixed together, it is called additive mixing. Red, green and blue are the primary colours for additive mixing. If all of these colours of light are shone onto a screen at the same time, you will see white.

This is different when you are mixing paints. Each colour of paint is absorbing certain colours and reflecting others. Each time another colour of paint is mixed in, there are more colours absorbed and less are reflected. The primary colours for adding paints or dyes, such as for a computer printer, are yellow, magenta and cyan. If you mix all of these colours together, you will absorb all the light and will only see black, because no light will be reflected back to your eyes.

You can easily experiment with this. Hold some coloured cellophane in front of your eyes and have a look around. Notice how some colours are changed and others look similar. Figure out which colours are being absorbed.

Nature of science

It sometimes takes a long time for new scientific knowledge to become widespread. For example, many people used to think that dogs could only see in black and white. It is now known that dogs have two kinds of colour receptors that allow them to see yellows and purples. Even though the initial experiment was done in 1989, many people are still unaware that dogs can see some colours.

One Color Tie Dye Shirt

Related content

Ever wonder why fluorescent colours look so bright? It is all due to energy, as explained in the article Light – colour and fluorescence.

One Color Literacy

Useful links

Experiment with mixing the primary colours of lights and paints using these simulations on the Causes of color website.

Find out about how dogs do have some colour vision and how they see the world in this article from Live Science.

Download this PDF from The Physics Teacher to find out how to make a colour light mixer using LEDs and a ping-pong ball.

Read this tutorial about Human perception, Spatial awareness and Illusions on Biology Online to learn about human perception.