What is color? Why do some objects look red, others green, others blue? Color is caused by reflected light rays. We see color because objects reflect light. Some thing that is red reflects mostly red light. In the same way, a green object reflects mostly green light. White objects reflect all colors of light. Black objects do not reflect any light. What happens to the colors of light that are not reflected? They are absorbed by the object. The darker the color, the less light is reflected and the more light is absorbed. Light that is absorbed is turned into heat. For this reason, dark-colored clothes are warmer in the sunlight than light-colored clothes. Which is the main idea of this passage?