Three experimental wallpapers: 
C-Thru bubble wallpaper, Tri-colour bubble wallpaper, "Stop!" wallpaper

Site: Simania (http://www.simania.nl/sdls/co/sdls-co.htm)

Last uploaded: 20-11-2006

Instructions: put the .wll file in [The Sims]\GameData\Walls.

Explanation:
The first wallpaper tests whether part of the wallpaper sprite
can be left transparent. Well, it can, but the result doesn't
look good.
The second one contains 3 palettes instead of 1. Each zoom has
a different palette, and so is a different colour.
In the third one, the sprites are not simply skewed/shrunk
versions of one graphic, but all separate graphics; the background
looks the same but the hand is a different colour both from
different views and at different zooms.

Disclaimer & conditions: This file can't possibly be violating any
copyrights, so I can skip that. It was made for fans to use in their own
installed Sims games. I don't mind people sharing this file, but it may
not be put up for download on someone else's page or included in 
commercial distributions.