Which is cooler, black or white clothing?

Many people believe that light-colored clothing is cooler than dark colored clothing irrespective of the time it is worn. Such is not the case. Assuming the material to be the same in other respects, there is probably little if any difference in warmth between black and white clothing under ordinary circumstances. Only in bright sunshine are white clothes materially cooler than dark clothes. This is because black substances absorb light while white ones reflect it. Light-colored material reflects more light than dark material does. Glass painted black and exposed to the rays of the sun is more likely to crack than is glass painted white. If two pieces of cloth, one white and the other black, are placed on a piece of ice in bright sunshine, the black piece of cloth will absorb the light rays and melt its way into the ice much faster than the white one will. Experiments show that if pieces of black, red, blue and white cloth are laid on a sheet of ice in the sun, the ice will begin to melt first under the black, second under the red, third under the blue, and fourth under the white. Thus white clothing affords the body more protection from the rays of the sun than does black clothing. Except in sunshine, however, the white fur of the polar bear is just as warm as the dark coat of the black beat. The white coats that nature provides for some animals in the winter are apparently designed for protective coloration without reference to warmth. It is the opinion of some horse experts that black horses are affected more by the heat of the direct sun than whites ones are. If that is true, the same should be true also of black dogs, cats and other black animals as well as of black people. There is some evidence indicating that dark pigmentation serves as a partial insulation from the sun rays and that dark-skinned peoples are less affected by direct sunlight than are light-skinned ones. This may explain the fact that darkskinned peoples seem to be more subject to such diseases as rickets than light-skinned peoples are even when their environment and diet are the same. Garments of closely woven white fabric are worn in tropical countries to protect the body from the bot sun. Such garments have high reflecting powers and prevent the transmission of ultraviolet rays to the skin. According to the United States Bureau of Standards, these rays pass through open-weave fabrics more readily than they do through closely woven ones, but it does not make much difference whether the color is black, white, red or green. White,. however, has been associated with coolness so long that white garments may have a desirable psychological effect in hot weather. The association of the properties of substances with their color is of great antiquity. That red flannel is warmer than flannel of other colors is an old belief that probably has no basis in fact. The notion that red is a warm color and white a cool color may have been suggested by the fact that fire and very hot objects are red, while snow and ice are white. Many people are extremely sensitive to colors, and the color of their rooms and offices has a decided psychological effect on their mental and physical well-being. Red, orange, yellow and black are generally regarded as “warm colors,” and green, blue and white as “cool colors.”