No glow paint would illuminate for more than a couple of minutes, most of that time it’s pretty dim. As far as I know all of these materials are effectively exactly the same. They will work after being lit with a flashlight. I agree, LEDs are the ticket. (The old ‘glow’ stuff on watches was radium (I had one, it was really neat) and tritium (military compasses and gun sights). Both of these glow on their own. Radium will glow longer than you’ll live, and the tritium lasts for about ten years. Neither is all that dangerous– unless maybe you worked in the place where they made them, or you got some and painted your tent with it.
What I find interesting is that LEDs offer so many possibilities, yet there are so many holes in available gear. A good powerful adjustable flashlight: no problem. There are lots of good ones. Headlamps: some really good ones (all of which have absolutely stupid interfaces. Yeah I use ’em and they work, they’re still stupid.)
You just need a single AA battery overall very low level. I clip my Fenix to the clip on my hiking pole (to clip the other pole to) Pointing up it lights the inside of my poncho/rainfly, but it would be too bright for your needs. At Costco and HomeDepot they sell headlamps that are really crappy as headlamps. They’re crappy because they aren’t very bright. Maybe that would work?