Abstract :
In today’s literature related to colour theory, the main colors are considered to Yellow, Red and Blue. To this theory, the mixture of Yellow and Red produces Orange, that of Red and Blue produces Purple and that of Blue and Yeloow produces Green. Therefore, the intermediate colours are known as Orange, Purple and Green. While in today’s literature Yellow, Red and Blue are regarded as primary colours, in printing technologies producing through pigmenst the main colours are Cyan Blue, Magenta and Yellow (CMY). From the double combinations of these main pigmente, the secondary pigments Red, Green and Blue (RGB) are produced. What is main/primary colur? What are the real main colurs? Are yellow, red and blue really main colours? What is the main colour blue like? Is red a main colour in red light or in pigmenst? Why are the main colours in light and those in pigmenst different from each other? Does the basic fallacy result from the classification of the spectrum formed through the refraction of white light in glass prizmas by Isaac Newton between1666-72 Or does it arise from the uncomformity between the colourants used by artists fro hundreds of years? Apaprt from all these, do the lack of a crosscheck for this theory set a ground for basic fallacies? May they arise from the conservative and traditional attitude of artists and art educators towards new knowledge? The goal of this study is to seek answers for the questions above and to have a detailed analysis of colour theories conflicting with each other in different sources under the shed of moder science and technologies in order to set the correct main and intermediate colours. The study is important because it unravels the inconsistencies in the sources on colour theories and sets the main, secondary and complementary colours. It will also be a useful guiding source for future studies. The physical formation sensed in out mind after light reflected by all objects around us reaches our eyes is called colour. Colour exsits together with light. Light is a physical phenomenon that collects all the colours in chromatic prism. Because of this collection, it is the element that gives colour to everything. In other words, when a colour is perceived, the real thing being perceived is light itself. The refraction of light into wavelengths through a glass prism in a dark room by Isaac Newton in 1666 paved the way for studies and researches in this field. In his study, Newton infiltared a thin beam of light equal to one single sun light into a dark room and manages to separate white light into a spectrum by pasing it through a triangular prism. Later, a colour cycle composed of colours and colour mixtures showing main and secondary colours was developed. In 1802, the physicist Thomas Young claimed that there are three types of conic cells in eyes that are sensitive to a definite light range. In his experiment, he passed light first from a slit and then two narrow slits measuring a certain prpportion of an inch. In the experiment, the light passing from two slits was reflected on a screen. As a result, Young found out that beams differed as separate and convergent ones and that bright arch were followed by dark arches at convergent points. Based on Young’s study, Hermann von Helmholtz put forward a more quantitative claim. In 1850, Hermann von Helmholtz improved Young’s theory: According to the reaction of conic cells to the light striking the retina, three types of wavelengths, which are short (blue), medium (green) and long (red) were set. The varying forces of the three types of signals set by conic cells are defined as a clour seen by the brain. In 1860s, Maxwell studied the use of three primary main colours. According to his studies, the three main colours do not include the combinations formed by no addition of three main colours and the main colours are not unique. However, if wavelengths were wide, they could form secondary colours. In addition, all of the colours perceived through such substractions were sensed by the use of a scale. Maxwell’s studies are considered as the basis of modern colorimeter. The experiments in 1920s comparing a colour spectrum and a visual RGB based colours show that RGB visual colours are sensed through a scale; however, this does not detect all the light (spectral) colours. Especially, there are deficiencies in the range of green. It was seen that when a certain amount of a suitable colour was added to red light, all colours could be produced. In 1931, Commission International de L Eclairage (CIE) carried out studies to set up a system in which all the tri-stimulus values could be shown positive on the x, y coordinate system. Visual colour matching led to the formation of horseshoe curve known as CIE chromatic diagram. This formed the basis of numerical colour measurements. Colour theories formed in the past according to experiences can now be explained in more detail through the adavancements in science and technology. Especially, Young’s analysis on the physiology of sight and his explanation of the function of conic cells that make colour perception possible helped Helmholtz and Newton to set the theory of three colours also thanks to physics experiments. According to the results of the experiments by Isaac Newton and Thomas Young, it can be said that white colours has all the colours of the sun. When light turns into an object that reflects all the white light, that object seems as white coloured to our eyes. Through the methods of elimination he used in his experiments, Young found out that he could reduce the six colours in the spectrum to three main colours (red, green and dark blue) in the same spectrum. Moreover, he proved that by a double misture of these three colours, the other three colours cyan blue, magenta and yellow could be formed. Through the mixture of these three colours, the infinite colours of the nature could be reached. In his experiment, Physicist Thomas Young did the opposite of what Newton did and he reformed the light and produced the white light by adding the six colours in the spectrum on the screen. In conclusion, when three beams of light- blue, intense red and intense green- were mixed, a bright white colour is formed and when two coours are mixed, a brighter light colour is naturally produced. In today’s printing technology producing colurs in pigments, Cyan Blue, Magenta and Yellow are used as primay main colours. Through the double mixture of these main pigments, the secondary main pigments Red, Green and Blue (RGB) are formed. In televisions, computers, cameras, tablets, mobile phones and outdoor screens acquiring images through light, Red, Green and Blue (RGB) are used as main colours. In environments with light, the double mixtures of Red, Green and Blue produce the seconday main colours Cyan Blue, Magenta and Yellow.