When white light enters a triangular prism, which color is refracted the least?

When white light passes through a triangular prism, it undergoes a phenomenon known as dispersion, where the different colors of light are refracted, or bent, by varying amounts. The degree to which light is refracted depends on its wavelength: shorter wavelengths, such as blue and violet, are refracted more than longer wavelengths, like red.

Red light, being at the longer end of the visible spectrum, experiences the least amount of refraction as it passes through the prism. This is primarily due to the fact that longer wavelengths travel more straightforwardly through materials and are less influenced by the changes in medium.

Consequently, while blue, green, and violet light have shorter wavelengths and are refracted more sharply, red light remains more aligned with its original path upon exiting the prism. This property leads to the observable separation of colors, with red light appearing least displaced from its initial course.