Part of the answer comes from optics. Violet light has the shortest wavelength on the spectrum of visible light, right next to the unseen ultraviolet, which only our skin detects. With its short wavelength and high frequency, the color purple contains the highest energy of all visible light. Figuratively, we can think of purple as the border between the visible and the invisible.
...the color you perceive is dependent on various factors such as lighting, surroundings, and your unique visual system, yet this does not mean that colors themselves are subjective.