I was kind of going for coral that looks like this:
And my attempts at recreating it.
**UPDATE** DIY coral under blacklights
I can do quite a bit with paint, but I'm thinking I could also use the hot glue gun and make droplets of glue for the 'fringe'. Or maybe yarn? That fun fur maybe... Course, the highlighters look pretty good under black light. Depends on availability of neon paint.
I was looking for a project that I could do just bit by bit, but lazily at my desk. Printing out and taping together hexagons would definitely fit that. Still some tweaking to do on this potential project.