250w seems hight to me as well. I have used for bearded dragons a 150 in a very cool room (60ºF) to get 100ºF so 250 seems quite hot. I suspect it could work if it was hung away from the top and perhaps a dimmer as well.
I don't usually suggest red as reptiles have very good near and true IR visual acuity. Blue, the other end of the scale I would suggest more, CHE are great as well, the no light issue is moot snakes see heat. Same can be said about deep blue I guess but how the heat pit information and visual information is processed or if it is separate or not is up for debate. That can only be guessed at but heat pits and eyes are processed by the visual cortex. It is likely they get used to both.
