Colour theory can change one’s direction in painting. (Stephen Quiller)

The order of the colours in the rainbow (the spectrum) is Red, Orange, Yellow, Green, Blue, Indigo and Violet. A mnemonic for this is Richard Of York Gave Battle In Vain.

Warm colours are the ‘sun’ colours: Red, Orange and Yellow. Cool colours are Green, Blue and Violet.

02 – GREEN

GREEN is one of the secondary colours, produced by mixing blue and yellow. Although it is a neutral colour it can look COOL when biased towards blue. – restful, does not dominate (surgeon’s gowns, traffic lights, snooker tables). Jeanne Dobie (referring to watercolours) writes that, “When striving for clean, clear greens, there is nothing to equal Viridian. This is a cool, acid green, rarely found in nature. Mixed with reds and yellows this produces an interesting range of greens. When mixing, remember that a little dab will often do it. Use a transparent red to avoid muddy areas”.

In landscape painting, you need greens to be subtly different from each other or the landscape will look flat. You can mix an extraordinary variety of greens with the colours on your palette. Green does not dominate (surgeon’s gowns, traffic-lights, snooker tables, etc.). Adrian Hill commented that, “With two blues and two yellows, practically all the different tints of green in nature can be matched.”

Greens are usually cold colours when they come straight from the tube. They can be warmed up by adding colours such as ochre, raw sienna or the cadmium yellows and cadmium orange. Joanna Carrington had a student whose favourite colour was green and he remarked to her that, “The trouble with landscape painting is that it means such a lot of green”. She felt that it was his lack of observation that led to that remark. Joanna elaborated on this: “How often is a field green? Grass can be white, grey, pink, yellow, brown, etc., or sometimes a chopped-up mixture of all or some of these, or of other colours. Green need not be the dominant colour in a landscape to make it convincing.”

VIRIDIAN is a bright clear emerald green. It is the hydrated form of Anhydrous chromium oxide, which became available in 1850. If you have only one tube of green, this is the most useful one because other greens can be made from blues and yellows, particularly a little cadmium yellow. It is probably the most important of the unmixed green pigments, with a cool, very pure tone very close to spectrum colour. It makes a good basis for warm, bright greens. Viridian is also suitable for painting man-made objects such as signs, garden furniture and painted woodwork.

SAP GREEN was originally made from ripe blackthorn berries and tends to be on the yellow side of the colour spectrum. It has a warm glow, which is useful for painting trees, bushes and foliage. Its warmth can be tempered by mixing with yellow, brown, blue or another green.

In Celtic myths the Green man was the God of fertility.
Bear in mind when you’re painting a landscape that whichever blue you have selected as the base colour for your sky should be used for mixing the majority of your greens.

04 – BLUE

BLUE is one of the three primary colours. It is a COOL colour that is restful and spacious (bedrooms, waiting rooms, consulting rooms). Barbara Dorf writes that, “to some, blue with its association with sky, expresses peace”. Renoir used bright blue instead of black to indicate shadows. In aerial perspective, distance is shown by using blue for faraway hills, etc. In reality, specks of dust and drops of moisture in the atmosphere cause light to scatter. Short wavelength light (blue) is scattered more than long wavelength light (red). This is why the sky appears blue and distant hills will look hazy blue. The term “aerial perspective” was coined by Leonardo da Vinci to differentiate it from linear perspective. The best approach is to divide a view into background, middleground (middle-distance) and foreground. Start with the background and strengthen the tones and colours as you approach the foreground. In aerial perspective, a simplification could be that blue retreats, yellow is intermediate and red advances. Some of the sky colour should be repeated in the foreground; the colour echo will bring them together. Skies don’t always need to be pure blue anyway

CERULEAN BLUE was first introduced in the 19th Century. In oil painting, this is a very useful colour for making delightful neutrals. It is biased towards green. Its name is derived from the Latin word caeruleus, meaning sky-blue. It is an old reliable colour for watercolours – cool, slightly towards green. A very difficult pigment to produce, genuine Cerulean tends to be expensive. Cheaper mixtures of Phthalocyanine Blue are available, but try to buy the best quality.

COBALT BLUE was also introduced in the 19th Century. It is obtained through the calcination of cobalt salts with aluminium.

ULTRAMARINE was originally produced from the very expensive natural material Lapis Lazuli. It was used since the 6th Century but was replaced after 1828 when the French government awarded a prize to the inventor of a synthetic version which became known as French Ultramarine. This creation of an artificial Ultramarine (a polysulphide of sodium) was a major breakthrough in the history of artists’ pigments. It’s a strong, warm, rich blue. Nearest to spectrum blue this is a beautiful blue. Some feel it looks crude by itself, but if for example it is mixed with Light Red it makes lovely warm, mauvish cloud shadows. When mixed with Carmine it gives very brilliant violets. Mixed with Cadmium Yellow it produces lovely greens.

PRUSSIAN BLUE is a ferric ferrocyanide. It was discovered accidentally in 1704 and has largely been replaced by the synthetic organic Phthalocyanine Blue. Used thinly, Prussian Blue is an ideal colour for painting shadows and adding atmosphere to stormy landscapes. Mixed with Cadmium Yellow, it produces very pretty shades of green. Two other popular synthetic mineral pigments first introduced in the 19th Century are Cobalt Blue and Cerulean Blue. Jeanne Dobie tells us that Ultramarine modified with a dab of Cadmium Red or Alizarin Crimson can create deep blues. In watercolours, because Alizarin is a staining pigment, a bright dark blue can be created.


Violet is one of the secondary colours and is a mix of red and blue. It is a neutral colour (tending towards COOL), sober, sombre, stately, distinguished, serious and contemplative (an ecclesiastical colour). Jeanne Dobie teaches that Alizarin Crimson mixed with a dab of Ultramarine Blue can create a rich dark purple.

WINSOR VIOLET is useful for modifying blues in skies and for making greys with yellows, browns and greens.

PURPLE LAKE is a warm colour for washing over pictures to create an impression of sunlit radiance. It is also suitable for painting shadows on warm days when the sun is high in the sky.

PERMANENT MAUVE is a soft warm colour that makes a natural companion for ultramarine. It has a strong blue basis and can be mixed with purple lake when painting flowers seen in window boxes and hanging baskets.

Purple is a colour of power, combining and balancing the two extremes of the electro- magnetic spectrum, the vibrant energy of red and the calm of blue, hot and cold.

Nature gives us purple in all its shades and tints; lavender, gentian violet, lilac, heliotrope, plum, damson, mulberry, grape and aubergine.

08 – RED

RED – One of the three primary colours, red is dynamic, activating, striking, restless and vivid. Red has an oppressive effect, demanding attention, radiating warmth and reducing space. For WARMTH and its ability to advance, Burnt Sienna can also be considered a red. Barbara Dorf reminds us that “red expresses fire or, in some cultures, splendour.” Neither Cadmium nor Alizarin red gives a true primary red, but a mixture of the two comes close.

ALIZARIN CRIMSON is, according to Kyffin Williams, “so powerful that it can destroy your palette.” It is to be used with discretion although many painters find it indispensable. It’s a cool intense red and very useful for tempering down Payne’s Grey for clouds.

CADMIUM RED is a brilliant colour taken from cadmium sulpho selenide, a chemical element. As you might expect, it mixes well with the cadmium yellows. The amount of selenium it contains determines the precise colour tone, which can range from orange to purple. In paints, Cadmium Red is gradually replacing genuine Vermilion.

LIGHT RED is a fierce earth colour – a little of it goes a long way. Never use it without adding another colour, such as raw sienna.

VERMILION is natural cinnabar known since prehistoric times. Manufactured from mercury and sulphur or by reaction of sulphides and mercury or its salts.

Red is regarded as a hot, warm colour and it symbolize aggression and high energy. It is also a sign of warning, danger and error. In the Western World it is also a symbol of love and passion.


ORANGE is one of the secondary colours, produced by mixing red and yellow. It is a WARM colour, aggressive and exciting. Although orange has approximately the same influence as red, it is a little less activating but still demands attention and radiates warmth. Some believe that the colour orange is good for digestion, if u look at it your mouth often starts to water.

CADMIUM ORANGE is a combination of cadmium red and cadmium yellow. As such it is useful for recording the warm appearance of fruits. It’s an excellent base upon which to build a succession of translucent tones.

Not a colour that everyone loves, but those who do are generally social and fun loving.


YELLOW is one of the three primary colours. It is a WARM colour that is quiet, cheerful, joyful, bright and (with red and orange) the colour of sunlight.

LEMON YELLOW is a greenish yellow, which can be used with alizarin crimson to achieve a duller orange. Mixed with ultramarine, lemon yellow produces a cool, almost greyish, green, useful for trees in a landscape painting. Lemon yellow has no staining qualities and its tinting strength is medium to low. It is an opaque colour.

CADMIUM YELLOW is taken from Cadmium Sulphide and many artists prefer it to the other yellows because it has no particular drawbacks. It mixes well with ultramarine blue to produce an intense shade of green, and is available in a range of tones from lemon yellow to orange. It is made by roasting cadmium oxide or carbonate with sulphur or by precipitation from solutions of cadmium salts.

CADMIUM YELLOW PALE is a bright yellow. Check that the ingredients are based on Sulphide of Cadmium. Substitutes bearing the name in their titles, such as Cadmium Yellow Pale Hue are inferior.

Traditionally, yellow has come from five main sources—mango, gamboge, orpiment, ochre and saffron. In the case of the mango bush, leaves from a certain area in India were force-fed and passed through the bladders of a certain type of cow before the urine-dyestuff could be harvested and exported in the name of Indian Yellow.

The color of the sunny disposition, the idealist. Intellectuals love yellow.

“There are painters who transform the sun into a yellow spot, but there are others, who, thanks to their art and their intelligence, transform a yellow spot into the sun.” (Pablo Picasso).

Information compiled by Dave Edwards during visits to Liverpool, Southport, Glasgow, Newcastle and Blyth libraries and also gathered from various Internet Web sites.


Kyffin Williams
Joanna Carrington
Barbara Dorf
Jeanne Dobie
Adrian Hill
Tony Paul
Robert Genn
David Fallows
Zarah Chapman



Blyth, United Kingdom

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A helpful way of remembering the colours of the spectrum and how they affect each other.

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