The device used to separate white light into its different colors is a prism.

Here's how it works:

* Refraction: When light passes from one medium to another (like from air to glass), it bends. This bending is called refraction. Different colors of light bend at slightly different angles.

* Dispersion: A prism is shaped in a way that causes light to enter one side and exit the other. Because of refraction, the different colors of light bend at different angles. This causes the white light to be spread out into a spectrum of colors, with red bending the least and violet bending the most.

Let me know if you'd like to know more about prisms or how they work!