Is light getting another color when travelling through a prism? When white light travels through a prism the speed of this light is slowed down. Now there is a relation between speed of light, frequency and wavelength.
So when a red light of 700nm enters a prism it will slow down at 0,9c. So wavelength = speed / frequency. Now you can theoretically divide the changes. So 600nm = 0,9 / 0,0015 or you can have 800nm = 0,9 / 0,0011. 
So the color in the prism can turns to 600nm or 800nm. Probably after leaving the prism the color gets back its original color.
But is it the case while travelling through the prism the color changes? Probably very tiny?
 A: When light enters glass (or another transparent material), its frequency stays the same and its wavelength changes.
In a comment, you say that you are using "color" to mean "wavelength". Well, I think you are using the word "color" incorrectly. According to a normal definition of "color", the color of light does not change when it enters glass. But the wavelength does.
ADDENDUM: Color has to do with how light appears to you when you see it. You can't see light while it's in the prism, you only see it after it exits the prism and enters your eyeball. Yes, the wavelength changes when the light enters the prism, but it changes right back when it exits.
A: This is a phenomenon called dispersion of light.

White light is a mixture of all colours which get separated when they pass through a prism. The refractive index or simply for lay usage the angle at which light bends when it enters from one medium to another depends on the wavelength of light. So the colours are not newly created, but they are just separated into a spectrum of light because of their difference in wavelengths, red with the highest and violet with the lowest wavelengths in the visible spectrum. So these two colours are at the extremities of the dispersion and the other colours being in the middle arranged in the order of VIBGYOR based on their respective wavelengths.
The same thing happens in the formation of a rainbow...one of nature's spectacular shows. I hope you got it.
