FR_ only the top of the retes stack is black to get that 135 basking spot without having to add another bulb. There is
5 levels below that with a hole all the way through. The bottom one being fully submersed in the dirt in which it dug a deep hole under the soil/sand substrate. My nile usually spends most his time on the level below the black, which is about 110 in that slot. All the other levels are normal light wood colored.