When an electromagnetic wave hits a surface the photons transmit part of the energy to the molecules of the surface. When parts of the electromagnetic waves are reflected depending on the wavelength that is reflected our eyes perceive the object as having a lighter or darker color. The more wavelengths are reflected the lighter the color of the object will be. The more wavelengths are absorbed the darker the object will appear to be. Therefore, those materials that absorb more wavelengths will be dark and those that absorb fewer wavelengths will appear lighter.