This section is from the "A Complete Dictionary of Dry Goods" book, by George S. Cole. Also available from Amazon: A complete dictionary of dry goods and history of silk, cotton, linen, wool and other fibrous substances,: Including a full explanation of the modern processes ... together with various useful tables.
Colors. In its relation to textiles, color is that quality or appearance of a fabric which is perceived by the eye alone independently of its form. Hue is the distinctive quality of a color; the respect in which colors may differ though possessing the same luminosity and chroma. Thus scarlet and crimson differ in hue, but buff and yellow chiefly in chroma. The word hue is always applied to the modifications which it receives from the addition of a smaller quantity of another color. Chroma is the degree of departure of a color from that of white or gray. Tone means the various modifications which a color is capable of receiving from white (which lowers its tone) or black (which heightens it). In fewer words, it is the modification which any color is capable of receiving from the addition of black or white. Tints are the colors considered as more or less bright by being modified by the addition of white. Shade is any degree or variation of a color, as lighter or darker. There are but three primary colors generally recognized: blue, red and yellow. These are called primary because they cannot be produced by compounding any other colors. The secondary colors are green, purple and orange. These are called secondary because blue and yellow make green; red and blue make purple, and red and yellow, orange. From these are derived the tertiary colors: olive, citrine and russet. Purple and green make olive; orange and green, citrine; purple and orange, russet. Thus we have the three classifications denoting all the colors proper extant. The varieties of tones, tints, hues and shades obtained from these three classes are as kaleidioscopic in their possibilities of combination as the alphabet of letters. The hand of man or the skill of the artist will never exhaust them. At the present time there are recorded processes for the production of 16,000 differently colored dyes, each capable of forming a different color upon textile fabrics.
Cattle are excited by a bright red color because that color is the complementary one to green; and as the eyes of the cattle are all day long fixed steadily upon the green of the herbiage on which they feed, articles of a red color must necessarily impress their vision with greatly increased and contrasted intensity, with the result of causing them to grow madly excited. Colors not only influence cattle, but human beings also. On this point some curious experiments are reported to have occurred in the hospitals of Italy, as to the effect of colors on the nerves of the sick and insane. In many hospitals of that country special rooms are arranged with red or blue glass in the windows, and also red or blue paint on the walls. A violent patient is brought suddenly into a blue room and left to the effects of that color on his nerves. One maniac was cured in an hour; another was at peace in his mind after passing a day in a room all violet. The red room is used for the commonest form of dementia - melancholy, usually accompanied by a loss of appetite or a refusal to take food. After three hours in a red room, a patient afflicted in this way began to be cheerful and asked for food. Many sane persons are curiously sensitive to color and shapes in surroundings, certain combinations effecting them with almost physical pain. As no surroundings are so inevitable as people's clothes, dress must be held responsible for a certain amount of intended pleasure or annoyance to others. It is said that one's own apparel is not without a certain influence on the wearer's own mind. A new color seems to bring a new atmosphere with it, and changes oddly enough the level of thought. Balzac, the French author, says that a woman's character always finds expression in her favorite color. A woman who prefers orange or green gowns is, he thinks, quarrelsome. Those who sport yellow hats or who go clad in black without cause are not to be trusted. White indicates coquetry. Gentle and thoughtful women prefer pink. Pearl-gray is the color of women who consider themselves unfortunate. Lilac is the shade particularly affected by over ripe beauties; therefore according to this authority, lilac hats are mostly worn by mothers on their daughter's wedding day, and by women more than forty years old when they go visiting.
Wool has generally the strongest affinity to color, when it comes to dyeing. Next to wool silk and other animal substances receive it best. Cotton is the third, and hemp and linen follow successively. As a rule pigments and dyestuffs do not produce permanent colors, and some substance is required to produce an affinity between the cloth and coloring matter. The substances that are employed to act as this bond of union are called "mordants," [see Calico and Dyeing] whose uses were known to the Egyptians and other nations of remote antiquity. Specifically, mordants in dyeing and cloth printing, is a body which, having two-fold coloring particles, serves as a bond of unity between them, and thus gives a fixity to the dyes; or, it signifies a substance which, combined with the coloring particles in the pores of the textile filaments, renders them insoluble in soapy and weak alkaline solutions. Mordant is also the substance previously applied to the goods in order that they may afterward retain in part the dye. The chemical activity of the sun's rays is well known, and certain colors seem to be decomposed and precipitated more readily under the influence of light. It is not surprising, therefore, to find that light should also have a very marked effect upon dyed colors. Under the prolonged influence of light and air almost all colors fade, and according to their relative behavior in this respect they are broadly divided into two classes, namely, those which are "fast to light" and those which are "not fast to light." Each of the seven colored rays of the spectrum possesses a different fading power. White light is the most active, then follow the yellow, blue, green, orange, violet, indigo and red rays. Direct sunlight is more energetic than diffused daylight. The light of the electric arc acts in the same manner as the sun, but is less powerful. According to the best authorities on colors, the presence of moisture assists very materially in the fading action of light, so that even some fugitive colors, dyed for example, with safflower annato or orchid, do not fade if exposed to light in dry oxygen or in vacuo. The term "fast color" generally implies that the color in question resists the fading action of the light, but it may also imply that it is affected by washing with soap and water, or by the action of acids and alkalies, etc. In its wide sense it means that the color is not affected by any of those influences to which it is destined to be submitted, but its technical influence is often restricted. Many colors may be fairly fast to washing with soap and water, and yet be very fugitive toward light; or they may be fast to light and yet very sensitive to the action of acids and alkalies. The term "loose color" generally implies that the color is much impoverished, or entirely removed, by washing with water or a solution of soap; it may, however, also mean that it is not fast to light. The word "permanent" as applied to color, generally denotes that it is fast to light and other natural influences. A "fugitive color" is generally understood to be one which is not fast to light. In the absence of any definite meaning being attached to the above terms, it becomes imperative in speaking of the fastness of a color, to refer especially to the particular influence which it does or does not resist.