is the change in direction of a wave at a boundary. When light is refracted as it enters a prism, each colour is refracted by a different amount. Because each colour has a different wavelength ...

It is then refracted away from the normal at the boundary between glass and air as it leaves the prism.

The finding adds nuance to fundamental physics while offering a new avenue ... but when you pass the light through a prism, you can see the rainbow of different photons within it.