Black is the color that absorbs the most heat among all the colors in the spectrum. Black objects absorb all wavelengths of light and reflect none of them. Absorbed light is converted to heat.
According to the University of California Santa Barbara (UCSB) ScienceLine, an object's color represents the wavelengths of light that the object reflects. For example, white objects reflect all wavelengths of light, red objects reflect red wavelengths, and black objects absorb all wavelengths and reflect none. Light energy can be converted into heat energy. Because white objects reflect all light, they do not have as much energy to convert to heat as black objects; therefore light-colored objects are typically cooler than darker objects. To demonstrate heat absorption of various colors, you can place pieces of variously colored construction paper in the sun and record their surface temperatures every few minutes. The dark colors become hotter than the lighter colors.