I've played Modded Skyrim for a long time but this is my first time getting this issue. I recently redid all of my mods after having some horrible CTD issues and finally got the game running again, but now after awhile of playing I start having new textures not load into the game and instead get just purple cel shading around meshes. It's not a missing texture problem because saving and reloading the game fixes it. I would be inclined to think maybe it's due to super high quality textures running me out of VRAM but I find this doubtful, aside from the High Resolution Texture Pack and some high quality skin I haven disabled the majority of texture improvement mods and I don't have a bad rig. My specs:

Intel i7 4790K @ 4GHz

Asus Maximus VII Hero Motherboard

Ultra LSP750 750-Watt PSU

16GB DDR3 RAM

Zotac GEForce GTX 970 (4GB VRAM)

2TB Seagate HDD Sata 6.0 x2 (one HDD for OS, one for game installs)

Windows 7 Professional SP1

2 ACER 21.5" LCD Monitors @ 1920x1080 Resolution (Connected via DVI)

I'm running a high mod load right now (238) but have ran similar high loads in the past with a weaker system and never had these issues. All mods except the official ESMs are loaded through Mod Organizer, cleaned with TES5Edit, ordered with LOOT, and Bash Patched. Usually the first textures to go missing are creatures or weapon/armor but it can be anything, I've seen whole buildings missing textures. So any idea what it might be?

Load Order:

I had a similar problem. Does reloading the game help? ie, you'll save while looking directly at one of the purpled-out textures, close Skyrim completely, and reopen and load that save. If the textures do appear this time, then VRAM is the most likely culprit.

You're running a lot of hi-rez weapon and armor mods. It makes sense that they'll be the first textures to fail to load.

Skyrim itself, being a 32-bit application, is probably the limiting factor here, not your machine (which is very nice. The only thoughts there are for you to pick up an SSD and install your OS/Skyrim there).

I seem to have resolved the issue, in another forum I was suggested to install ENBoost and increase the memory allocation in it's ini, since then I've not had any noticeable issues.