All the underwater rocks, iron shortswords and hourglasses are purple in my game. I read that it probably had something to do with not uninstalling a mod right. Only problem is I don't know where to find the files I need to get rid of. What's the best way to fix this? Should I just uninstall Oblivion and reinstall it? would that work? Any help is appreciated.

Purple indicates a missing texture. This can be caused by faulty texture replacers, wrong archive invalidation or a wrong texture path in the mesh. If you installed your mods without obmm (or bain) before, i suggest you start using it because it can prevent issues like these.
For a wrong texture path in the mesh, open up your data folder and browse to
Meshes/weapons/iron for the shortsword (i forgot what the other were but you can get their path in the cs)
If the mesh is there, delete it. If not, this isnt the priblem.
For archive invalidation, simply google to get multiple features that can help this.
If you installed a texture replacer without obmm, you can check the file readme for uninstalation instructions. If they arent there im afraid i wont be of much help.

Always remember to read a files instalation instructions and to use obmm as it can prevent issues like these.

Obmm link:
http://www.tesnexus.com/downloads/file.php?id=2097

Always always always make an OMOD for any texture or model replacers.

If you uninstalled any kind of replacers easiest thing I would think is installing OBMM, and then make an OMOD with whatever replacer you just uninstalled and then REINSTALL it as an OMOD. Then you can uninstall the OMOD and it should remove whatever was there(easier than trying to hunt down individual files).

Make sure you are using archive invalidation. In OBMM click utilities, archive invalidation, verify bsa redirection is selected and click update now.

There is no utilities...only settings....it says archive invalidation but there's only a box to check.