We can answer the question above if we first know the answer to the question, “why are dark things dark?” An object is dark, even when it is facing the light because instead of reflecting the light from its surface, it absorbs all the rays of light. Radiant heat and light are basically the same things, so when light-colored clothes reflect the light that strikes them, they also bounce back the heat that accompanies the light rays. While any light-colored objects will reflect all the light and heat that strike it, even the whitest snow will gradually melt under the sun’s rays as it is too powerful to reflect.
But while light objects keep only a little light and heat that falls on them, dark things absorb almost all of the energy received, so they tend to get warm. For example, if a shirt made with white cotton is dyed black, it will feel warmer to your skin than before.
Everything is made of atoms and molecules, including clothes. If you have a white-colored shirt, the molecules that make it up vibrates based on the amount of energy that it gets, and for this case, the energy that it receives is heat and light energy. Because it is a light color, its molecules will bounce off the energy with ease, but with a black shirt, the molecules will contain the energy and will continue to vibrate faster as long as it is exposed to heat energy.
Studies show that black objects like dark shirts and pens radiate infrared if they get sufficient energy. But this infrared is invisible to the naked eye. Most of the infrared that the Earth gets is from the sun, hence the reason why black objects that are exposed to the sunlight radiate infrared.
Both a white shirt and a black shirt will have the same temperature after getting it out of the washing machine. However, one may notice that the black shirt gets warmer is a faster pace than a white shirt when it is exposed to the sun.
White is not the only color that is able to reflect light, as there are also yellow, pink, light blue, and other bright colors that can do the same. Pastel colors are usually the ones that feel cooler to the touch, mainly because its main color is mixed with a little bit of white.
Shiny objects are said to reflect more light than matte colors, which is why dark objects that have a shine to them are much cooler than their flat-colored counterparts. However, the shininess of an object cannot really change the tier list of colors that receive more heat, since shiny white can still reflect more light than shiny black.
The ability of light objects to reflect more heat is the reason why most spaceships, including the ones built by NASA for the Apollo space missions, are primarily white in color. The whiteness of the entire spacecraft allows it to be cooler in space because if it is black, it will absorb more heat from the sun and cause problems for the vehicle like overheating. Spacecraft is not the only white-colored object in space, as astronauts also wear white to prevent not only their suit from overheating but their bodies as well.
The white material used to create the clothes and other space objects is cold the Beta cloth. The Beta clothe is made with silica fiber that is durable and resilient against almost any minor damages. This cloth is sometimes found above a multi-layer insulating blanket that protects the object from leaking oxygen while keeping it at a stable temperature. White is also used as the main color for the interior of the spacecraft, as it allows it to be brighter in the eye despite having little to no lights. However, black is also used in some rooms of the spacecraft as it is more capable of retaining heat, which is perfect for people who want to stay warm in the often cold temperatures of space.
There are criticisms surrounding the use of white paint to put color to the exterior of rockets and spaceships, and it mainly revolves around the fact that paint adds weight to the vehicles. On the other hand, many experts say that they would rather have a heavy spacecraft than a warm one, as the engines will be able to handle a little more weight, but they won’t be able to handle overheating when it gets exposed too much to heat and the sunlight.
There are many applications to this process other than using it for space flight. Many construction workers would rather wear white shirts than black ones since they are regularly under the sunlight, and those who live in the colder parts of the world would have darker-colored clothes to help them stay warm.