The rainbow's color that appears last is violet. In the visible spectrum of light, colors are arranged in the order they are seen within a rainbow: red, orange, yellow, green, blue, indigo, and violet. Violet has the shortest wavelength of the visible colors, lying between 380 and 450 nanometers. This positioning in the color spectrum reflects the way light is refracted or bent when passing through water droplets, leading to the formation of a rainbow after rain or in the presence of mist. Violet, while often overlooked, completes the beautiful arc of colors that visually captivates many.