I was wondering if it was common for a veil to turn lighter when they go to sleep? During the day she is usually a darker green but at night she turns a shade lighter. Does this mean she is cold or is she fine?
It is normal I would really think that this happens for two reasons. One they do not have to use their color to regulate their body temperature. Two they are at their most relaxed when sleeping.
I personally think that they may choose different sleeping postures to help control the escape of the heat they have already aquired. Just an observation I have made with mine along with some experimenting to see how they react.