The process of a prism separating the different colors of light is called dispersion.
The process you are referring to is called "dispersion." When white light passes through a prism, it undergoes dispersion, which means it separates into its component colors. This happens because different colors of light have different wavelengths, and when light enters a prism, it undergoes refraction, causing the different wavelengths to bend at slightly different angles. As a result, the colors of the spectrum (red, orange, yellow, green, blue, indigo, and violet) become visible as they spread out or separate from each other. This creates the beautiful phenomenon known as a rainbow.
