I have to agree that CHE is much better than any sort of night light. It doesn't matter if it's not "bright"; beardies can see color. Which means that the light from a blacklight looks exactly the same to them as it does to us. (It might even seem brighter to them if they can see more of that end of the spectrum than we can, which is entirely possible.) In short, while it may be darker than full daylight, it WILL keep awake any dragon that requires total darkness to sleep.
Now, I have to say, that isn't true of all dragons. It's mainly true of young ones. Older dragons, I am told, tend to be able to sleep whenever and wherever they feel like it. But you might want to switch to CHE just to be certain.