I would DEFINITELY opt for a blue over a columbian, ANY day. ANY tegu but a columbian...they have a very deserved reputation for being very difficult, aggressive pets. Of course, there are people who have had occasional successes--but, they are few and far between. A red, a blue, and argentine b/w, an extreme giant...all good choices.

Getting a columbian would be nothing like having one of the others I mentioned--two totally different worlds.