This mod gives you the possibility to apply face overlays in papyrus by “converting” looksmenu face tints into headparts. It’s a resource and a workaround (hopefully temporary) for modders who want to apply face tints in their script instead of manually via looksMenu Ui.
This mod doesn’t contain any texture, so make sure to also download the looksmenu face tints you want to use (only textures are required).
This is an alpha version and more like a proof of concept, it's open to suggestion and improvements.

How it works:
Each facePart contains a modified vanilla head .nif and a material file pointing at the face tint texture. I'm no game artist so the hardest part for me was to find the right settings in order to imitate the looksmenu blending mod (“blendingOp”). All the HeadParts use vanilla assets, so face morph should be fully functional. 
It’s a work in progress, I only added support for a couple of vanilla face tints and two mods.

How to install:
I uploaded two versions (esl flagged esp), install only one:

• FormList: this version requires Garden of Eden Papyrus Script Extender and is highly compatible with RobCo Patcher. Any one can make headparts put them in a formlist and inject it into this plugin formlist.
• Struct: this version contains all the face tints I converted so far, doesn’t have any requirement other than F4SE and original texture mods but not really compatible with form injection.
• I merged both plugins and scripts together, so the mod will only use GOE functions if you have it installed (V14.5 or higher).
• If you are updating from V1.0, make sure to restart the quest in console: "StopQuest SFT_Main"/"StartQuest SFT_Main". You only need to do it once.
• If you are using HiPoly Face Redux, install the optional patch and let it overwrite the main archive. (Fusion girl only for now).
  

How to use this mod:
The source files are included and the script is simple and self-explanatory. (Read the article).

Supported Face tints:

• Vanilla face tints: All Vanilla tats, should have the same magazine requirements as Looksmenu counterpart. Some Damage face tints (Boxer 1 to 4) 
• Mod added face tints: See requirements.
  

How to make your own headparts:
I will add an article to explain it in detail.

Limitations:

• Vanilla unique NPCs are not supported, you need to force the game to generate their appearance data at runtime by flagging the actor as "is CharGen Face Preset". Can have negative impact on framerate. Most mod added NPCs should be fine though.
• For Leveled NPCs, the face tints will be temporary, as soon as you load a save, the texture will be gone.
• Can't use material swap on head parts. Each Face Tint requires its own material and nif file.
• Can't use TextureSets either because most face tints require transparency (fine-tuned in the .BGSM).
  

Future updates:

• Add support for male characters.
• Add support for more face tints (mostly on request).
  

Credits:
@JB. and all the authors who created the original face tint textures supported by this mod.
@spicydoritos & @kziitd for showing me the way.
@CRWREX for valuable information about material file tags.
@LarannKiar for the excellent script extender (GOE).
@Blaze69 & @Maxie for all the informations about headpart limitations and bugs.
@zilva for SNIFF (huge time saver).
@EgoBallistic, @VaultBait, @ENGINE and @Safe Muffins for suggestion and support.
@Anyone who takes the time to help other modders and shares his work and knowledge.