I am told that this new system of route marking in the mountains is being trialed in the UK, and is very likely to be adapted throughout Europe and the USA.
luminous painted rocks to reduce getting lost after dark
I think the most important thing to remember is that, whilst very large numbers of rocks will need to be treated with this paint, the paint will hardly show up in daytime. Only becoming visible after dark. This has been done to counter concerns by some mountain walkers that daubing paint over so many rocks would despoil the mountains.