It's simply called their "glow" wax and is from their black magic graphite wax line, billed as a warm/wet weather wax, comes as a toxic looking red puck. Turns green when it gets wet, and that means anything it's on or gets on.
I don't think it actually glows in the dark, but leaves more of a neon green slime trail behind. I had a buddy use it a few seasons ago and it made a quite the mess, on the snow, his hands, his roof rack, etc. Never seen anyone use it at night or since at the resorts. It sounds like it could be fun, but while it's not supposed to have any chemical/issues. I can easily see a resort not finding it amusing at all that they have bright green lines all over their slopes.