Final answer:
True, the color of an insulator or semiconductor is determined by the wavelengths of light absorbed. The material's perceived color is the result of it absorbing certain wavelengths and reflecting or transmitting the complementary colors.
Step-by-step explanation:
The statement that the color of an insulator (semiconductor) is given by the wavelengths of light that are absorbed by the material is true. The color we perceive from a material is actually the colors that are not absorbed, or in other words, the material reflects or transmits these colors while absorbing the complementary colors. Semiconductors, like insulators, have energy bands. If the energy of the incoming photons is lower than the band gap of the material, such as with infrared photons with a wavelength longer than 1.1 µm in silicon, they will not be absorbed. This lets them pass through as if the silicon were transparent. White light, when passing through a colored substance, will have certain wavelengths absorbed which results in the object displaying the complementary color to the absorbed wavelengths. This relates to the general principle that colors are due to the ability of the material's atoms to absorb certain wavelengths while reflecting or reemitting others. For example, if a material absorbs light in the 500-520 nm range, the remaining light will make it appear red.