Both, and neither, with the terms you offered us. In general, the visual difference is more intense colors and such. But you may also see all kinds of patterns and recurring themes on walls and whatnot. Last time I did it the ceiling was covered in little shimmering blue/green versions of this with the texture of a seashell. they scintillated and covered everything, but you have to learn to relax and almost unfocus your eyes sometimes to see it. set and setting is crucial, as crucial as the lsd, in hallucinating.
best way ive found to describe it is that things morph. you wont just see a banana sitting in the middle of the room but perhaps a chair might slowly shift its appearance until it becomes a banana or something. but yes all senses seem to be enhanced and i suppose can trade places with each other. ie. you might begin to see sound or feel it for that matter. This is a bit less common, wont happen to everyone or on every trip.
Most people just get a distortion in the vision, things seem to bulge, melt, grow/shrink, rippling surfaces, trails, etc. Depends on the dose and the person obviously. Taking enough will send you into a state where you no longer remember having a body and feel like your just a consciousness observing some wild shit going down. One thing I've always gotten, even on low doses, is neon spiralling geometric patters at the point where the eyes grasp an image, and when this is observed in particular, it blossoms and grows into absolutley fantastic imagery.