Black absorbs more heat because it also absorbs more light, and light energy changes into thermal energy, which gives off heat. Light is absorbed or reflected from an object. For example, blue objects reflect blue light and absorb other colors.
White reflects light, absorbing little to none of it, so it also reflects heat. Black, however, absorbs all colors of light. Because of the large amount of light absorbed, more thermal energy is produced. This phenomenon explains why wearing white clothes is preferable to wearing black clothes in the summer. "Albedo" is a term dealing with a surface's reflective qualities. A 0 percent albedo means complete absorption of light, and 100 percent means complete reflection of light. Accordingly, black has a very low albedo.