Shades and Tones of Green
In the creation of light in visual display units, there are three primary colours, which in combination can be used to produce the many thousands of shades and tones which go to make up the coloured images on television screens and visual display units. Of the three primary colours, red is surely the brightest and most vivid, and blue is usually considered the coolest. But green is perhaps the most tranquil, the most passive, and the easiest on the eye. Green is the colour of nature, and it is my favourite.
In this article, I look at the shades of green, and how they can be produced just by utilising different proportions of light intensity. I also consider the naming of shades of green, and why this colour—perhaps above all others—is the one with which we feel most comfortable in our lives.
Naming of Green Hues
The names we give to shades and tones of, for example, the colour red, are so exotic—such words as claret, crimson, vermillion, and cerise are rich and evocative.
The naming of shades and tones of green, it must be said, are a little less imaginative, and a little more prosaic. Forest green, pea green, olive green, and apple green, spring to mind. As indeed, does spring green. I suspect this may be because there are just so many subtle shades of green in the natural world that there was never any need to invent new names or take names from other more romantic languages such as French or Latin. Instead, we could just look to the plant or vegetation type which best typified the hue.
Some of these are illustrated as best as possible on this page, though the main purpose of this page is to show how different shades and tones are created using the RGB colour system, so many of the colours here are merely referred to by their red-green-blue intensities.
A Confusion of Colours
Unfortunately, the naming of colours is not a very precise art. Anyone can name a colour whatever they like, and many do. Manufacturers and suppliers of inks, paints, and dyes can call their range of shades and tones anything they like. The result is that one colour tone may have several different names while the same name may be applied to several different tones according to the authority you consult. What's more, colours generated by light in a visual display unit, will not be exactly replicated when printing on to paper. Different monitors, different printers, and different ink compositions will also vary in the results they produce.
In this article, only one method of creating colour will be used. As readers will be viewing on a visual display unit, I will employ the RGB system which is described below, and hopefully, colour reproduction will be faithful on the monitor you are using.
In this article, I can only give the briefest of explanations of the RGB system and the colour codes which are employed as an integral part of describing how the different shades and tones of green are produced.
If you wish to understand exactly how the huge range of different intensities of red, blue, and green light may be manipulated to produce all different colours in a visual display unit, please look at my other work.
Creation of Green Using the RGB Colour Model
The colours we see all around us in the world are a manifestation of all the different wavelengths of visible light. If none of these visible light wavelengths are detected by our eyes and brains, then, we see this as Black.
On the other hand, if all of these wavelengths are present together at maximum intensity, then we see any image created as White. And by varying the proportions and intensities of these wavelengths of visible light, we can produce every single colour we can imagine.
But in visual display units such as televisions and computer monitors, it's been found that it is not necessary to use all the wavelengths of light; a combination of just three—Red, Green, and Blue—is sufficient to achieve many thousands of different shades and tones. Light in each of these wavelengths is emitted in proportions which can be rapidly and subtly altered to produce different tones. This is the principle behind the RGB colour creation method.
In my writing, the proportions of the three primary colours in the finished tone is codified by the percentage intensity of each primary colour wavelength emitted. Under this system, the maximum intensity of each wavelength is 100%, and the minimum intensity is 0%. Higher intensities of light make the finished colour lighter and brighter, while lower intensities of colour makes the final colour darker. Green, of course, is one of the primary colours of light in the RGB system, so pure green is generated by only the green wavelength of light. In pure green light, red and blue emissions are zero, as can be seen in these examples which also show the codes for white and black shades:
- 0% (R) : 0% (G) : 0% (B) - A total absence of any light is black
- 100% (R) : 100% (G) : 100% (B) - Combined emission of maximum intensity red, green and blue light is white
- 0% (R): 100% (G) : 0% (B) - The brightest pure green will have this coded value on the RGB scale; that is, it will have the full intensity of green, but there is zero emission of red or blue
- 0% (R): 50% (G) : 0% (B) - This, of course, is still pure green because there is no red or blue influence, but it is less intense; ie: it is dark pure green
As soon as the percentage of red or blue emissions is raised above zero, so other colour tones are produced, and the degree of greenness is reduced. As the intensity of all three primary colours is increased, so the final colour produced moves closer to white, as we will see in the shades and tone descriptions to follow. In these descriptions, I have used percentages of RGB intensity which seem to me to give the colour rendition which is most closely associated with a particular tone. It is by no means definitive, but I think that these descriptions of shade and tone could generally be accepted.
Shades of Pure Green
Above, I showed illustrations which demonstrate how the shade of green will vary with the intensity of light emission from the pixels in a visual display unit. All of these illustrations are of pure green shades rather than green tones—that is to say, green is the only light emission. There is no red or blue contribution to the images, so the only influence on these colours is one of intensity—how light or dark the end shade is.
As can be seen in the illustrations, I have presented shades in which the intensity diminishes from 100% (maximum intensity) to 75% to 50% to 25%.
These are all pure greens, and they become darker in shade as intensity is reduced, until one may reach a pure green so dark that it is almost black. There are, of course, paler greens than any of these, but these can only be created by the addition of both red light and blue light to the mix—this is because high intensities of green, red, and blue light combined together, alter the final tone in the direction of white light. We will see this effect in the next section.
As indicated in the previous section, in order to lighten the tone of green in RGB systems, we must introduce red and blue light, which gradually moves us closer to white light. A few examples of this are shown here.
In each case, the intensity of green light is at its maximum, so the tone of the end hue is predominantly and clearly green. However, as we go through the three tones illustrated, the intensity of red and blue light gradually increases from 40% to 60% to 80%.
In all the other tones illustrated in this article, proportions of red and blue light are varied to illustrate how each of these primary colours affects the final tone of hues in which green is dominant. First, we will look at combinations of green and red light, and then we will look at combinations of green and blue light.
Green With Red Light
In this section, the colour of green is influenced by the addition of red light, but no blue light. When red light is added to green light, the tone gradually moves towards a more and more yellowish colour (pure yellow is equal proportions of red and green). The tones chosen here are chosen partly to represent a range of yellow-tinged greens, and because they include some of the best known green tones.
In the first tone, we can immediately see the influence of red. Although the shade is quite dark (because green is at an intensity of only 50%), there is a distinct tint. In fact, equal proportions of red and green create yellow in the RGB system, so this could theoretically be described as a very dark yellow. However, there is an obvious similarity to the colour of green olives here, so we call this olive green—a very ancient name which dates back at least to the late Middle Ages.
In the second example, there is a greater intensity of green light, creating a lighter shade—the colour of green apples or apple green, first used as a tonal name in 1648.
Chartreuse was named in 1884 for its colour similarity to the French liqueur, which in turn was named after the Chartreuse Monastery near Grenoble (where the liqueur was developed for medicinal purposes in 1764 ). Lawn green is a very similar tone, but a less attractive name!
One can see in this section how all the tones are distinctly more yellow than those featured earlier. The fourth tone features red light which at 70% is now approaching the same level of intensity as green light—consequently, the colour is not merely pale, but very yellowish. This is yellow-green.
Green With Blue Light
In these tones, there is no red light, but now the dominant green tone has been influenced by the addition of blue light. In the first example, which sometimes is described as spring green (a name which dates back to 1766), the influence of blue light does not seem marked (though it is more clear if you compare this tone with shades and tones illustrated above).
The second example—blue-green—is slightly darker, as the intensity of green light is reduced. This also means that blue light is making a proportionately larger contribution to the whole, and we are now seeing a distinctly blue tinge to the hue.
The third tone included here is a hue recognised as teal in which equal proportions of green and blue light produce a colour very reminiscent of the colour of the head feathers on the duck known as a common teal.
Green With Blue Light and a Hint of Red
Three well-known tones of green feature a strong influence of blue light as in the above section, but also a proportion of red light which subtly alters the final hue.
The first of these is mint green, first used as a colour name in 1920. In this tone as interpreted here, intensities and proportions of green and blue are very similar to those of the blue-green tone illustrated above.
Sea green supposedly is the colour of the seafloor seen from the surface. Light intensity is rather less than in mint green, so the tone is darker.
Bottle green was first used as a colour name in 1816. Green has long been a traditional bottle colour as a result of green impurities which once made it difficult to create colourless glass. Also, dark glass may reduce the effect of sunlight on the bottle contents.
Two More Well-Known Shades of Green
Forest green as a colour term is first known from 1810, and the connotation is obvious, as a representation of the average colour of trees in a forest (though of course the true colour of trees in a forest will depend upon the predominant tree species, and will also vary with the effects of sunlight and shade).
A different form of forest green was reputedly and famously worn by Robin Hood and his men in Sherwood Forest. The name of Lincoln green actually comes from the city of Lincoln which in the Middle Ages was a centre of cloth production, and it was here that the colour was produced from a blend of blue and yellow dyes. The name was first known to be used in relation to Robin Hood in 1510 in a collection of tales.
Both these tones are quite similar to middle shades to pure green illustrated above.
The History of Green
One might suppose that plant dyes have been the ubiquitous source of natural green pigments throughout the centuries, but this is not really the case. Although plant dyes have been used, they often lack permanency, and the majority of extracted vegetable dyes actually produce yellow tones, rather than green.
Of course in painting, as we all know, yellow, and blue combined together can produce a green colour, so pigments have been created in this way. However, throughout history it is the minerals of various metals, and more recently chemically processed compounds, which have given us the most successful of green pigments.
Possibly the first green colour extracted on a significant scale for the purposes of pigmentation was malachite, from the copper carbonate mineral of the same name. Crushed and ground to a powder. Evidence of malachite as a pigment has been found in ancient Egyptian tomb paintings, and remained in favour in Europe until the 16th century.
The Greeks introduced verdigris as a pigment. Verdigris is familiar to all as the blueish-greenish colour which stains metal copper on buildings of a certain age, and it was artificially created by the Greeks by exposing copper metal to acetic acid and then scraping off the blueish green crust which forms.
The very word verdigris comes from the French 'vert-de-gris' (literally, the green of the Greeks). Later the pigment was obtained by various other similar methods—the Roman writer Pliny, described a method involving suspending copper plating over fermenting grapes. Wine itself has also been used to create this effect. Until the 19th century, verdigris was considered the most vibrant of all green pigments.
Other pigments which have been used since Greek times included green earth, made by the grinding and mixing of the natural minerals celadonite and glauconite. The proportions in which these were mixed, determined the tone of green created.
Thanks to industrial chemical plants, a new generation of greens were introduced beginning in the late 18th century, and continuing throughout the 19th century. Many of these processes utilised copper compounds, but other metals such as chromium and lead and cobalt have also contributed green pigments. In the light of this new age of pigment manufacture, the use of natural pigments declined.
Nevertheless, as an interesting aside, not all of these industry produced greens have proved entirely beneficial. For more than a century the cause of death of Napoleon Bonaparte was unclear, but it is now widely believed that he died inadvertently from arsenic poisoning, because Scheele’s green was a copper arsenite paint used in green wallpaper at his home in exile on St Helena. A century later Monet was using emerald green which also contained arsenic, in his famous water lilies paintings.
Indeed, the potential dangers of arsenic-based green pigments did eventually become known to the Victorians, and this led to one of the more memorable comments on the adverse effects of industrialisation. Following the discovery that high levels of arsenic had been found in the green pigment used to dye wool, the Times Newspaper in England asked:
"What manufactured article in these days of high-pressure civilization can possibly be trusted if socks may be dangerous?"
Green—the colour of life. The very word green is almost synonymous with life, deriving as it does from Old English verb grēne or growan or the earlier grœni, meaning "to grow." The first recorded use of the word as a colour term dates to about 700 AD.
In the section, Naming of Green Hues, I was rather dismissive of the lack of imagination behind the names of shades and tones of greens. I wrote:
There are just so many shades of green in the natural world that there was never any need to invent new names. Instead, we could just look to the plant or vegetation type which best typified the hue.
Unlike some other colours which have an intriguing history of development, and which have borrowed extensively from ancient or foreign languages such as Greek or Latin or Arabic in the names given to shades and tones, the names for green hues have come naturally to English.
Therein, however, lies the beauty of green. It is the colour of nature, readily seen in every shade and tone describable just by taking a walk or a drive into the country. The tones have never needed to be created by man to be appreciated. Green is the colour above all others which has become implanted into our brains over thousands of years as the most familiar, and therefore the colour with which we feel most relaxed.
Although our lives would be poorer, we could live without some of the colours of the visible spectrum—but to live in a world without green would be intolerable.