Like alcohol, LSD can do brain damage (I'm ok with the legality of both regarding adult use in conjunction with drug-education, but that's a side issue).

On that issue of seeing other colours & the like, salvia divinorum is legal in the UK & most of the US: it sort of takes apart one's consciousness and puts the pieces before you in a sort of abstract & visceral way with profoundly vivid hallucinations/delusions.

It doesn't have that brain-damage-potential/toxicity-level LSD does, -anyone interested in temporarily taking apart their respective consciousness and possibly seeing a new colour could try that (I'm just sharing the knowledge)... it can have a therapeutic effect at best, although money really should be used to save lives. Salvia divinorum could perhaps have research potential for understanding consciousness, including colour processing... somehow I suppose!

I used it and believed reality was coming to a finish because I had 'figured out the answer'... all I 'had to do' to sort of 'finish up reality and see what is behind the scenes' as it were, was go outside and save a little boy in my drive-way. I went out, the boy wasn't there and I realised how vulnerable the brain is to delusion: I found it insightful, at least!