These are the relative indices of refraction. If you neglect the index of refraction of air, which is 1.0003, then these are the indices of refraction for this color in this glass.
Index of refraction increases with frequency of light, or you could also say that it decreases with wavelength of light. This is only true for light waves, and it is a material-specific relationship between index of refraction and color of light.
I feel it is rather foolish to identify colors of light by wavelength, for precisely this reason. When light changes speeds in different media, its wavelength changes in order to compensate for it. The wavelength of red light in a vacuum might be green light in glass. Frequency, by contrast, is always the same.
Answers & Comments
n = 1.52 for red light
n = 1.529 for green light
n = 1.54 for violet light
These are the relative indices of refraction. If you neglect the index of refraction of air, which is 1.0003, then these are the indices of refraction for this color in this glass.
Index of refraction increases with frequency of light, or you could also say that it decreases with wavelength of light. This is only true for light waves, and it is a material-specific relationship between index of refraction and color of light.
I feel it is rather foolish to identify colors of light by wavelength, for precisely this reason. When light changes speeds in different media, its wavelength changes in order to compensate for it. The wavelength of red light in a vacuum might be green light in glass. Frequency, by contrast, is always the same.