White's Tree Frog Questions

[Kurt]

My question: Could this be harmful to the frog? Should I take it out and totally clean/redo the cage? His tank is 80 in the day time but when I turn the heat lamp off at night it gets down to 70-65 temps.)

You can leave the wood in. The tempertures are fine. Most likely he/she has turned brown because the tank in on the dark side either light-wise or color-wise.

But I noticed that the under side of his legs were red. Is this normal for White's Tree Frogs? (I never saw it mentioned in the care sheets)

Yes, for the hidden areas of the legs.