Blue, Red, and Yellow are simple, or primary colors. Green, Violet, and Orange are compound, or secon dary colors. The mixture of Blue with Red produces Violet. The mixture of Blue with Yellow produces Green The mixture of Red with Yellow produces Orange. These compound colors vary in hue according to the proportions of the simple colors of which they are formed: thus, by increasing the quantity of blue in the mixture of blue and red, we produce purple, indigo, etc. The same effect takes place with Greens. The primary colors are simple and pure, they cannot, like the secondaries, be produced by the mixture of other colors. It is evident that the color of the primaries cannot vary as color (or in hue), but only in intensity, at least so long as they are kept pure, but the hues of the secon daries may vary infinitely, according as one or the other predominates. THE TYPE, OR STANDARD, OF COLOR. To avoid misapprehension when speaking of colors, it is necessary to refer to some invariable type or standard of color, so that when speaking of Blue, we may not be in doubt as to whether the color represented by Prussian Blue, or by Cobalt Blue is meant. This type, or standard, is supplied by nature in the prismatic spectrum, and-although in a weaker degree in the rainbow. Therefore, whenever we speak of pure colors, those representing the colors of the spectrum must be understood. They are called also normal colors. ON THE MIXTURE OF COLORS. We must never lose sight of the fact, that the results predicated of the mixture of colors, taken theoretically, are not obtained by mixing pigments, or paints, and dyes. Theoretically, the mixture, or combination of the colors of the prismatic spectrum, by means of a lens or concave mirror, produces a ray of white light; but when we mix pigments representing those colors, taken as pure as we can possibly obtain them, the mixture is not white, but gray or black, according to their intensity, etc.: For every Blue pigment contains also either red or yellow; Every Red pigment contains also either blue or yellow; Every Yellow pigment contains also either blue or red. And although, as we have said, the union of the blue, red, and yellow of the spectrum produces white, the union of blue, red, and yellow pigments produces gray or black. If we had pigments that were in color as pure as those of the spectrum, their mixture would also yield pure colors. Ultramarine is the only pigment that approaches a prismatic color in its purity, but even that has a slight tinge of red in its composition, causing it to appear violet. We can take gamboge as the representative of pure Yellow, carmine as that of Red, and Prussian blue as that of Blue. In mixing pigments to obtain pure secondary colors, we shall obtain a better result if we select such as are free from the color not essential to the compound. Thus, to obtain a pure green, which consists of blue and yellow only, we must take a blue tinged with yellow rather than with red, and a yellow tinged with blue rather than with red; if we took either of those pigments tinged with red, a quantity of black would be formed by its mixture with the two other primaries, and the green would be tarnished or broken. So long as pure blue and yellow are mixed together, in varying proportions, but without the addition of the other primary color (red), the resulting compound color, green, remains a pure color. Such is the theory, and the practical result is the same if the pigments we select to form the mixture are both free from the third primary. When the three primaries (pigments) are mixed together in equal strength and proportions, the resulting compound is black. But if they are mixed in unequal strer gth and proportions, the mixture is gray, colored by the primary or the secondary in excess in the Com pound. Normal Gray is forined by mixing a black with a white pigment in varying proportions, producing various tones of Gray. By adding a primary or a secondary to normal Gray, we produce a colored Gray. There are as many classes of Gray as there are pri mary and secondary colors, and as many hues of Gray as there are hues of these pure colors. What are com monly called Tertiaries, are, in fact, colored Grays: thus, Russet is red-gray, Citrine is yellow-gray, Olive is blue-gray. If the primaries are mixed in unequal proportions, or are of different intensities, the mixture is a gray: If the blue is in excess, the mixture is a blue-gray. gray. If the blue and the red are in excess, the mixture is a violet-gray. If the blue and the yellow are in excess, the mixture is a green-gray. If the yellow and the red are in excess, the mixture is an orange-gray. When two secondaries are mixed together the gray that results is colored by the primary which enters into the composition of both secondaries, thus: In mixing Green with Violet, the Gray is colored by Blue, that being the primary in excess. Green consists of Blue and Yellow. Violet consists of Blue and Red. The compound contains twice as much Blue as Red or Yellow. In mixing Green with Orange, the Gray is colored by Yellow, that being the primary in excess. Green consists of Blue and Yellow. Orange consists of Red and Yellow. The compound contains twice as much Yellow as Blue or Red. In mixing Violet with Orange, the Gray is colc red by Red, that being the primary in excess. Orange consists of Red and Yellow. Violet consists of Red and Blue. It is understood that the colors employed are of equal strength and proportions. COLORS OF OBJECTS. The colors of objects are supposed to be due to a power they possess of absorbing certain portions of the colored rays that make up a ray of white light, and of reflecting others. The reflected portion being complementary to the portion absorbed; and if added together they would constitute white light. Thus a red-colored substance is considered to absorb blue and yellow, and reflect red. A green-colored body absorbs red, and reflects blue and yellow, A white substance, then, in conformity with this view, reflects all the rays that constitute white light, while a black substance absorbs them. Bodies reflect a considerable portion of white light as well as colored light, according as the surfaces are smooth, glossy, polished, rough, channelled, etc. The optical effect of a color is greatly modified by the condition of the surface of the colored body; thus, pieces of silk, cotton, linen, woollen, and velvet, although dyed of exactly the same hue and tone of color, appear to be of quite different colors. The depth or intensity of color presented by velvets, and certain flowers, such as heartsease, etc., is due to the surface being channelled, ridged, or furrowed. COMPLEMENTARY COLORS. As white light is composed of three colors, Blue, Red, and Yellow, the color that is missing from the compound is termed the Complementary Color; thus Blue is the complementary of Orange (Red and Red is the complementary of Green (Blue and Yel- Yellow is the complementary of Violet (Blue and By this it will be seen that the complementary of a primary color is the secondary composed of the other two primaries, and vice versa; thus: Orange (red and yellow) is complementary to Blue. If the Blue is tinged with yellow, its complementary, If the Red is tinged with blue, its complementary, If the Red is tinged with yellow, its complementary, If the Yellow is tinged with red, its complementary, If the Yellow is tinged with blue, its complementary, CIRCUMSTANCES WHICH MODIFY A COLOR. A given color, Red, for instance, may experience many modifications, so as to appear very different from what it really is, according to the circumstances under which it is viewed. It may be modified in its color: 10. By being placed in contact with Blue, the red appears yellower. 20. By being placed in contact with Yellow, it appears bluer. 30. By being placed in contact with Green, it appears purer and brighter. 40. By being placed in contact with Black, it appears duller. 5. By being placed in contact with White, it appears lighter and brighter. 60. By being placed in contact with Gray, it appears brighter. |