When light passes through a prism, it bends, or refracts, based on its wavelength. Among the visible spectrum, violet light bends the most. This phenomenon is due to the fact that different colors of light travel at different speeds when they go through various mediums, like glass. Violet light has a shorter wavelength compared to other colors, which causes it to slow down more and thus bend more sharply as it enters and exits the prism.
In contrast, red light, which has a longer wavelength, bends the least. This bending creates the familiar rainbow effect, with violet on one end and red on the other. So, to answer the question: violet is the color that bends the most in a prism.