Various textures make up the game's flareful looks. The textures in the game progress as the game goes on. Typically, they will become more and more distorted-looking and sinister further down. The Grey Man seems to reset the textures, meaning you have to deal with more dreams to reach the strange textures again.
The files on the LSD game disk show up to five kinds of texture packs. Most people would split them into these categories:
Kanji: Textures are modified to have Kanji writing on them.
Downer: Textures are more sinister looking, and are often distorted.
Sexual: Textures are more sexual, with some elements of the downer texture pack
Ancestral: Textures are Japanese art depicting people in the Feudal era. This texture pack will only appear in a certain locations.
According to TV Tropes' page on LSD, a player lasted in the game for so long that the textures became a glitchy black. This is probably due to a glitch, considering there are only five texture packs available for each object.