Hm, well, I'm no expert or even a keeper of White's Tree frogs, but I'll tell you what I know.

Often, when using a UVB/UVA light, a frog will be brighter. I'm not sure whether this applies to White's tree frogs, but even so.

I honestly suggest a red or black heat light, and a UVB light. Just may help your frogs, being frogs from I assume is a warmer climate.

Another Canadian! Ay!

I'd have a day-night cycle for the frog. 10-12 hours for the day part. Maybe, dim the lights or turn them during the evening.

Coconut fiber substrate is perfect.

Goodluck with your hopper!