Right now you can only specify the index of refraction N. However, there are several public databases that contain glass types and their index of refraction as a function of the wavelength of incident light, usually in the form of coefficients for some given functional form. It is straight forward to implement this: find a comprehensive database containing glass types and their coefficients, create some function that takes a glass type and wavelength and outputs an index N, and allow a surface to have a variable index of refraction that calls this function when needed.
Right now you can only specify the index of refraction N. However, there are several public databases that contain glass types and their index of refraction as a function of the wavelength of incident light, usually in the form of coefficients for some given functional form. It is straight forward to implement this: find a comprehensive database containing glass types and their coefficients, create some function that takes a glass type and wavelength and outputs an index N, and allow a surface to have a variable index of refraction that calls this function when needed.