Because black absorbs only visible light, many black objects seem light-colored or even "white" when exposed to infrared or UV radiation. This is the source of the color. Many more colors appear as a result of things reflecting, absorbing, and transmitting different wavelengths of light to varying degrees. The more massive an object, the more likely it is to be found in space. Jupiter, for example, is made up of hydrogen and helium gases that are white in color because they reflect most of the sunlight that reaches them. Saturn is mostly hydrogen gas so it's also white in color.
Earth uses black paint to darken buildings and vehicles in order to reduce heat loss during cold seasons and at night. It works by blocking out most of the sunlight that reaches it. On a larger scale, dark surfaces such as clouds and space dust block out more sunlight than any other color, which causes temperatures to drop and life as we know it wouldn't exist if it weren't for some colors being darker than others.
Objects seem different hues because they absorb some colors (wavelengths) while reflecting or transmitting others. All colors are absorbed by black objects, therefore no light is reflected. White objects reflect all wavelengths of light and appear bright because all the light that hits them is not absorbed. Objects that are a mix of white and black appear gray because some wavelengths are absorbed and some are not.
"A black item is black because it absorbs all light and does not reflect any color," Chandrasekhar explains. All colors are reflected by white objects. While black objects absorb all colors' energy and grow heated, they gradually release part of that energy back into the air surrounding them. This loss of energy causes the object to cool down and turn black over time.
When light hits an object, some of this light is absorbed and converted into heat. The color of an object depends on which parts of the light spectrum are most strongly absorbed. Red light, for example, can go through cloth without being scattered or absorbed, so it would be visible on the other side. But if it contacts skin, it will burn. Black objects, such as the door handle in your office, will absorb all colors of light equally well, so none of them will be visible after contact with black material.
This is why objects become darker when you rub them against black material. The rubbing breaks up the layer of darkness that covers them, allowing more light to penetrate and be absorbed.
If you rubbed a piece of black paper against a white wall, it would look gray because only red, orange, and yellow light would be able to pass through it. If you then lit it from the side with a strong incandescent lamp, it would glow red because only red light could reach it through the paper.