I would guess from your responses, he's too hot and dry. The LED lights shouldn't be putting out enough heat to affect anything, but obviously there is heat coming from somewhere and it needs to be lowered. I know it's retail and you need the frog to be visible, but he would be significantly happier with enough substrate to bury in and fake plants to hide under. I do have a sick frog at the moment who has an infection and his color is a bit lighter than normal.