heh, the first thing that comes up when you search "LSD colorblindness" is this bogus study from 1982 that suggests LSD causes "irreversible impairment in colour discrimination"
A chronic impairment of colour vision in users of LSD - PubMed
Forty-six users of the hallucinogen lysergic acid diethylamide were compared with 31 controls on a test of colour discrimination an average of two years after their last exposure to the drug. Controls performed better than users, and LSD users without flashbacks performed better than users with...
pubmed.ncbi.nlm.nih.gov
