Colour harmony, the combination of colours that is soothing to the eye. If you look at a landscape through coloured glass, you get a strange, but not a pleasant impression, which becomes all the more unpleasant the longer the predominance of a colour lasts. We also find it uncomfortable when the intensity of the colours, i.e. by holding smoked glass in front of it, is reduced too much or shaded (grey in grey), as well as if the saturation of all colours is too low (pale, weak colours) or too high (screaming colours). Only when all the colour-sensing nerves are kept in activity in a normal manner, even if not simultaneously and in the same way, is the impression a pleasant one. A landscape in which the green of the meadows and the blue of the sky are almost the only colours that we perceive, loses the monotonous and unpleasant the instant an evening or dawn is added, or yellowish and reddish colouration of tree leaves etc. However, the eye sometimes creates the missing colours as contrasting colours (s. face) by itself, since the sensitivity of the irritated nerves is quickly reduced, so that the other colours which are always present in white and grey are perceived more strongly. It is precisely in this strain on the eye that the cause of the disharmony of the colours lies, and the eye must be spared it as much as possible. One might think that juxtaposing saturated complementary colours would make the best impression. However, this is not the case insofar as the contrast occurs to a particularly high degree at the border of the colours and the border gives a restless, flickering impression due to the constant movement of the eye and the afterimages that are formed (s. face). This can be prevented by separating the complementary colours with strips of black or white or bright golden lines. Then the impression is, if not downright unpleasant, at least, as one likes to say, less of character, because we have the idea that where there is peace and order there is a single ruler, not two separate powers ruling independently of one another. Of the two colours, therefore, only one, the leading colour, must be saturated, the other shall only appear desaturated or broken, but it must cover a correspondingly larger surface area so that the optic nerves are challenged equally. For example, a uniform made of equally sized pieces of yellow and blue cloth in saturated colour would be unattractive, but the impression is a good one if only small pieces of saturated yellow colour are attached to a large area of blue mixed with black or white (dark grey blue, light grey blue). The impression is improved even further by adding white or black lines, i.e. in the form of bandoliers etc.
It is more expedient to replace complementary colours by colour chords or triads of three colours which, like complementary colours, yield white in the additive colour system (or black in print), i. e. which are 120° apart on the colour wheel, like yellow, red, blue, or orange, green, violet. The triads which may be extrapolated from the 30-part colour wheel, along with the associated shades, are listed in Hoffmann’s »Systematische Farbenlehre«. Otherwise, the same principles apply. One of the colours must be saturated and predominate as the leading colour, but shall only cover a relatively small area. Of the other two, it is expedient to use one as desaturated (tinted with white), the other as shaded (shaded with black). When matching the colours, the eye must inspect each colour only for a brief moment, otherwise many illusions will arise as a result of afterimages. For this reason, the colour wheel (s. Adobe colour Wheel) is an invaluable tool, enabling the technician to select the associated colours of an accord simply by the numbers. It is also permissible to use two colours of a triad as saturated colours, which then to a certain extent represent one of two complementary colours, but the impression loses character, it turns mild (harmony of large spaces).
Furthermore, it is advantageous to accompany a saturated colour with shades and hue shifts of the same colour (harmony of small spaces), i.e. placing light blue or dark blue next to saturated blue, but the former must tend towards green, the latter towards violet, based on the concept »cold light, warm shadows or warm light, cold shadows«, where cold colour refers to colours tending towards the blue end of the spectrum, and warm colour to those colours tending towards the red end. A spread of hues gradually ranging from white to brown-black creates a pleasant impression, and this is improved the more evenly spaced and the more numerous the individual steps are. In particular, the following practical rules apply: red and green are closest to each other in the hierarchy of hues; blue and orange already form a greater contrast; yellow and violet are only tolerable if the yellow tends toward dark green and the violet is bright; green and violet are a better match than blue and violet. White raises the tone of neighbouring colours and strengthens the intensity, so it is mainly used for contrasting harmonies. Black creates nice harmonies with dark colours and nice contrasts with light colours. Blue and violet go very well with black, then in turn: red and pink, orange, yellow (but glossy) and green; the latter, however, gives the black a reddish, faded appearance in a very predominant area, i.e. black tips on a green background.
Grey, unlike white, is able to form several analog harmonies with black, but it less pleasing than black when placed next to blue and violet; it is a bland impression alongside pink, but goes well with orange. Tinted grey is best chosen so that it contains the complement of the adjacent colour, i.e. orange or Carmelite (brown) grey next to light blue. Less pleasant colour combinations can often be improved by interposing white and black. Of the colours which do not add up to white, red and orange do not go well with one another, because they are too close together on the colour wheel; however the relationship improves if is white is interposed. Purple and green-yellow, on the other hand, tend to get along better without mediation. Red and blue only fit if they are far apart and if white intervenes. White also has an improving effect between blue and orange, but not between yellow and violet. Orange and yellow next to green and blue do not look good, not even when white intervenes; for green and blue alone the intermediate position of white is necessary.
Black often improves the disharmony between individual colours even better than white; it fits very well between red and orange and is recommended with red and gold, with orange and bright yellow, with orange and bright green. Black always goes well with dark colours and shades of the luminous, less so when it comes alongside a dark and a luminous one. Similarly, grey is often used to reduce or cancel disharmonies between individual colours. Between two colours it fits better than white if one is dark, the other bright and both contrast too much, and better than black if the dark colour predominates, i.e. with orange and violet, with green and violet. In all of these improvements in colour harmony, however, what matters is the saturation and ratio of dark and bright colours; i.e. white with red and orange is less suitable the higher the saturation, whereas black works well alongside the highest saturations. In the event of great disharmony in the colours to be separated, it is always better to separate each from the other than to separate the pairs of colours with white or black; e.g. white-blue-white-violet looks better than white-blue-violet-white; black-red-black-orange better than black-red-orange-black. These recommandations all relate to fairly equal areas of colour; if the areas are very significantly different in size, such as in gardens of different sized flower beds, some modification occurs.
Instead of bringing colours that appear at the same time into harmony, one can also let harmonious colours appear one after the other, similar to sounds, creating colour melodies, so to speak. This is the purpose of the so-called play of colours (chromotropes), doodle top, the kaleidoscope and the phoneidoscope. Castell even constructed a colour piano (1725–35) that should be to the eye what musical instruments are to the ear; improved by Ruete, it consists of two discs that rotate on a common axis at little different speeds. The front disk has one or two opposing cutouts, and the rear one is divided into several, about twelve, sectors alternating colour chords with black or white, so that the colours of the chords form parts of concentric rings, while the others sectors are all white or all black. As a different part of the rear disc always moves into the incised field of the front one as it rotates, one sees one colour chord after the other, now emerging from the light, now from the dark and then disappearing again. Even if the impression that is produced by this is a pleasant one, it cannot be compared to that of an appealing piece of music. The reason for this rests in the fact that the eye is that sense which appreciates the spatial. Beautiful colours lacking beautiful form therefore provide little pleasure. Early on, attempts were made to demonstrate a certain correspondence between the harmony of colours and musical notes, and Hoffmeister composed several octaves by changing the colours in various ways; he constructed whole and half colours, thirds, fourths and fifths, without being able to achieve more than his predecessor. In contrast, Radicke (1839) first stated in his »Optik« that »in light there is a connection between the perception of colours and a simple proportionality of the oscillations, as in the case of sound«. Unger (1852) based his law of colour harmony on this and established a colour scale that corresponds to the arrangement of the musical notes in the scale. Goldschmidt also seeks to express both ways of harmony with a single formula. All of these experiments come to the conclusion that the frequency of the rays of the spectrum, to which the colours of the colour wheel correspond, encompass almost an octave; e.g. the number of oscillations of the outermost violet (800 trillion per second) is twice that of the outermost red (400 trillion), and if these colours are applied to the colour wheel sorted by wavelengths, the arrangement is roughly similar to the equal distances of primary colours and the juxtapositioning of complementary colours. However, this is not exactly the case. Kolbe, for example, who drew such a colour disk, finds the following distribution: red from 15–45°, orange to 105, yellow to 165, green to 211, blue to 316, indigo to 330 and violet to 340°. Purple would have to be inserted between 340 and 15°.
- »Farbenkreis in 15 Abstufungen und 20 Anwendungstafeln. Nach Brückes Physiologie der Farben« (Wien 1877)
- Chevreul: Des couleurs et de leurs applications aux arts industriels (Par. 1864)
- Goldschmidt: Über Harmonie und Komplikation (Berl. 1901)
- Guichard, Harmonie der Farben (Frankf. a. M. 1882)
- Hoffmann: Systematische Farbenlehre (für Buchdruckereien, Zwickau 1892)
- Jännicke: Die Farbenharmonie (nach Chevreul, Stuttg. 1902)
Source: Meyers Großes Konversations-Lexikon, 6. Auflage 1905–1909