Just a note here: Toxins are transmitted between frogs through the skin and the water they share, the places they sleep, the glass they stick to, all surfaces will retain hints of the toxins your frogs secrete. As one leaves behind the other absorbs, slowly poisoning the other over time.
It would be hard to find a forum on the web where the mixing of frog species is not frowned upon.


As for your question on lighting, nocturnal frogs have no need for UV lighting, but your frog's colors change with mood, to blend in, and when ill.
Some frogs will bask and change from green to brown and back with no reason.

We provide lighting to simulate the change in day to night and to give the frogs the option to bask.
I still use 2.0 lighting in my Whites viv and have no reason to change. Today one Whites was dark brown, while one directly in front of him was light gray. Both were similar distances from the provided lighting.