It is Isaac Newton published the refraction phenomenon for the light pass through a prism on 1672, that established the foundation of modern optics. In the article, Newton claimed that color , now been well known to be the appearance of wavelength, is an intrinsic property of light and does not arise from passing through a media. It also indicated that the speed of light differs from different color of light in a media, so as the refractive index.

Now we are experienced enough to calculate the refractive index  with different wavelength by Sellmeier equation shown as below.

where n is the refractive index, λ is the wavelength, and Bi and Ci are experimentally determined Sellmeier coefficients.

We found an powerful website from internet. It contains a database of the coefficients for different materials for us to get refractive index from different wavelength. Please refer to the following.