i believe the term is "eidetic vision"... it is the point at which (in a trip) that one's imagination overlays and overrules what's in front of them. for example, when one would normally look at a cup, the mind already knows what a cup is, so it knows that cups don't distort or melt or change color for no apparent reason. however, look at the same cup during the trip and one would no longer see a cup, and the mind no longer "assumes" the cup's physical properties. to your mind, it is merely color, shapes and lines that may be manipulated as the mind might imagine it to (and you'll see it as the subconcious mind imagines it). the progression of drawings actually illustrates this effect quite well. they also illustrate that lsd initially affects the nervous system, and asking even a talented artist to draw at certain stages would prove fruitless. if one knows and trusts their mind enough (requires more work than most people think, ask a buddist monk), very interesting observations and perceptions can be had that would otherwise not be. if one does not, some very scary things can be had that would otherwise be unimaginable.
not entirely my ideas... man by the name of faber birren... one of the masters of color theory in terms of it's physical, and psychological effects on people. although he does tend to wax metaphysical at times, too, but then again color does have metaphysical value in different cultures (for example purple for christians, red for chinese, etc). and by default, it would be difficult to do any kind of comprehensive study on color and not record things that some cultures use to render meaning or inner knowledge from the intangible (like color effects), so things like psilosciben(buddists and others), peyote(american indians), and of course lsd(a lab scientist's attempt-cum-modern seeker) come into the picture. if anyone here is in school for design i recommend reading birren and johannes itten. they are the equivalent of say, jan tsichold(sp?) for typography. somwhat dated, but good history lessons to be sure.