A manure cart explodes and player is covered in s**t. Also smells really bad (disease for 12hrs). I have copied the texture files for this and changed them, the colour mainly but where are they in CK and how can I get mine into CK and make it specific to this poop explosion?

I only know where the blood on the screen derives from:

textures/blood/ screenbloodalpha01opt.dds

and screenbloodcolor01opt.dds

since I made them invisible a week after Skyrim was released

Those are the files I changed.

You should be able to dynamically change it using SKSE, the path to these textures are located in the Settings (Gameplay > Settings in the Creation Kit)

use an art object and a visual effect. Is the same way used when you read an Elder Scroll where signs appears in front of you. I used that for my Gray Cowl of Nocturnal mod.