Hey gamers,
Let me start off by saying if you know nothing about Skyrim tweaking this will all be jiberish to you.
Anyways, for those of you with beefed up computers that have been messing with .ini tweaks, this is a big FYI.
Ever since Skyrim update 1.3, anyone who has tried reverting their uGrid back to 5 from a higher value following the comfirmed manual here (scroll all the way down), has had the same problem. The skyrim menu logo and loading screen turn red and the game crashes during the load-up.
To fix the loading screen discoloration, just go to your Skyrim/data file and type .ini in the search bar, then delete whatever .ini file comes up no matter what it’s named (it is not whatever it appears to be labeled as.)
As for the save file, there is no confirmed fix… 
if I find one i’ll let you know asap.
FOUND A FIX FOR THE uGrid CRASH PROBLEM!!
Open a working save game – open the console
alt tab and open your skyrim.ini in your mygames/skyrim
change to these settings:
uExterior Cell Buffer=36
uGridsToLoad=5
save file
go back in to your game and in the console type: refini
close console
save game
quit
load