Every wavelength of light is affected to a different degree by the refractive index of a material and as a result changes direction by a different amount when passing from one medium (such as air) to another (such as glass or water).
Every wavelength of light is affected to a different degree by the refractive index of a material and as a result changes direction by a different amount when passing from one medium (such as air) to another (such as glass or water).