a real and entirely unverifiable phenomenon i have experienced is a sudden and "permanent"[^1] perceptual deepening of color saturation. twice this has happened after drugs and once it has... kind of just happened. and it tends to affect colors in the red/orange/magenta range the most. it's cool! perception is so fascinating
P.S. pretend my footnotes work lol.
[^1]: insofar as such a thing could be called "permanent". what i mean is not a temporary effect that goes away after whatever may have induced it has "worn off", but rather carries forward in a noticeable way