how to prepare coloured pigments?
Chemically, pigments fall into a number of large groups, but these are often arbitrarily divided into two major groups. The first group comprises pigments that contain nitrogen; it includes hemoglobins, chlorophylls, bile pigments, and dark-colored pigments called melanin, widespread in many animal groups and the chemical that is responsible for variations in the color of human skin. Related to melanins are the indigoids, of which the well known plant pigment indigo is an example. Riboflavin, which is also known as vitamin B12, is one of a number of pale yellow to green pigments that are produced by several plant groups. The second group is formed of pigments without nitrogen. Carotenoids are members of this group, as are the important plant pigments called flavonoids. In leaves, flavonoids selectively admit light wavelengths that are important to photosynthesis, while blocking out ultraviolet light, which is destructive to cell nuclei and proteins. Flavonoids are also important in flower color, in particular providing red and blue pigments. Bright fall colors are produced by the conversion of colorless flavonoids, called flavonols, into colored forms, called anthocyanins. Quinones provide many yellow, red, and orange pigments, including several useful dyes derived from insects that feed on plants containing the quinones. Cochineal, for example, is a red pigment obtained from the fat cells of scale insects that feed on cactus plants.
Pigment does not might desire to do with pores and skin inevitably, a paint could be tinted with a pigment. curiously it is likewise a dry colorant, many times an insoluble powder. pores and skin colour is set by using the quantity of melanin in one's pores and skin, relative to ranges of exposure to the sunlight.