When the colors that make up light are absorbed by an object, the energy is converted to heat. Objects that absorb more colors within the spectrum create more heat. This is demonstrated by the color absorption of objects that appear black, which heat more quickly than more reflective surfaces.
Color is the result of the interactions between the atoms in an object and the electromagnetic frequency of the light being transmitted. Color that is not absorbed may be reflected back to the observer or scattered. The potential for an object to absorb color is due to the vibrational frequency of the object's electrons. If the frequency of the electrons matches the frequency of the light being received, specific colors, corresponding to those frequencies, are absorbed while other frequencies get reflected. The relationship between the light absorbed and the electrons causes the electrons to interact with those of neighboring atoms, which converts the vibrational energy into thermal energy. Once the light energy is absorbed by an object, it is not seen again.
The use of light to measure absorption and reflection is a helpful tool to physicists, who can learn a lot about the physical properties of an object from the way it interacts with light. Among these properties are transparency and opaqueness. Some materials can be transparent to certain wavelengths of light, while others can be entirely opaque, which tends to increase their ability to absorb heat.