My question is this: Firstly, even on our planet, florescent materials "pop" at dusk or on cloudy days. I'm assuming that around an F-type star with much more UV radiation, the effect would be more dramatic. How MUCH more dramatic could you see this being?
You'd still get a lot of visible light, so it's more like having very powerful black light lamps everywhere. Might be quite anticlimatic, in that you get a little more glow but it still gets outshined by daylight.
Secondly, even if it were not more dramatic, this seems like it would wreck the camouflage of any hunting predator or hiding prey.
Meet the scarlet macaw.
This critter lives in, among other places, the Amazonian jungle. It is the only place in the world that compares to Australia in terms of everything that moves wanting to kill you.
The jungle foliage is green. These [redacted] are [redacted] bright red with bright yellow and bright blue wings, as if saying to all JAGUARS and BOA CONSTRICTORS and HAWKS:
COME AT ME [REDACTED], I AM RIGHT HERE WHERE YOU CAN SEE ME
As if these birds weren't scandalous enough, they are also loud. Not only in decibels but like they can't shut up.
So how does a critter that only eats insects and small fruits manage to survive without becoming the easiest meal ever to any predator? Specially in a place that is full of jaguars, which are tough enough to hunt anacondas underwater and who are known to mimic bird calls?
You see, flamboyance among macaws is a means to show that they are tough and cunning enough to defeat any predator that comes their way. It's like saying "I am a living neon sign that says free food and yet I manage to live an average of forty to fifty years in the wild". All the weak ones were removed from the gene pool millions of years ago. The survivors are some of the nastiest animals I've ever met.
I would let an owl or hawk or even an eagle perch on my shoulder or forearm anyday. I don't want to get within three feet of a macaw. They aren't as murderous as the birds of prey, but they can grasp with a lot of strength too and have very sharp claws, and unlike the predators macaws have no respect to other animals, their own lives or even God in Heaven when triggered.
I once saw a DC comic where some villains were comparing heroes. They came to the conclusion that Superman is usually nice, and Batman can break some of your bones but Flash is the worst because after he defeats you he will talk to you and that's absolutely humiliating. What does this have to do with macaws? Well, like parrots they can mimic the sounds of other animals. And the way they do this is by imitating the calls of predators. The kicker though is that while sometimes they do this to prevent conflict, they also love doing this AFTER winning a fight against a predator. Pure sadistical taunting.
That is not to say that they don't get eaten here and there. Jaguars sometimes get desperate, and boas are too dumb to ponder if they can get dinner unharmed. But overall macaws survive because usually they are not worth the hassle.
Your day-glo fauna might just have the same vibes. A predator might look at something that shines like a pop singer wearing a disco-ball costume under a floodlight and then, either by instinct or prior experience say to itself: "eh, I'd rather eat dirt".