Reef safe paint?
 

Looking to paint some PVC pipe black. What kind of paint do u recommend?

Krylon Fusion works well IME unless you have urchins. I used krylon the first time around but second time I just used purple PVC primer which gives a coraline effect which also blends in well over time.

+1 on Krylon. Good stuff.

I have a blue tux urchin...

It will remove the paint, a purple primer may be a better option either by itself or applied before paint so when paint is removed by the urchin you'll have a dark purple backing rather than straight white. Coraline will grow on it anyway so the primer will blend in nicely.

You could put live rock epoxy which is purple all over the pipe. I bet that the urchin wouldn't scratch it off but I don't have an urchin so I don't really know.