Does ultraviolet light look purple? No. NASA explains that ultraviolet light sits beyond the range visible to human eyes.
Where does the glow come from? Fluorescent materials absorb UV and return some of that energy as visible light. That response, rather than the UV source, creates the color we see under a blacklight.
How does the palette read? Black and Midnight Blue form the dark room. Indigo, Blue Violet, and Violet trace the glow, while Ghost White marks its brightest point.
