Thats a really interesting thought about the blind hallucinations. I really dont know, if the color information was never in your mind to begin with, i really don't think one would be able to see colorful hallucinations if you were blind. Taking LSD or whatever doesn't actually put colors or anything for that matter into your mind, it just plays with what is in there and what you see/hear/etc...
I'm open to correction if anything i said is wrong...just my opinion. Im sure there has been a blind person who has taken a hallucinogen. and i bet it's documented somewhere on the internet
Anyway, has anyone noticed problems with pupil dialation after using hallucinogens for a couple years or so? Im talking about pupils being dialated when sober. I didnt have this problem before I started using (abusing really) ecstasy, and LSD/mushys/etc., but now I seem to get headaches when I am driving at night, or when i'm around alot of lights at night, and sometimes during the day.