I've found a way to fix the issue of pawn heads having a reddish tint to them (much more noticeable with darker skinned pawns). The issue itself seems to be a shader issue with the original mod, in where the intended head shader isn't being used and is instead using the rotting corpse shader (just an assumption, take explanation with a grain of salt, I'm not much of a modder lol).

A temporary fix is to find the HeadType.xml file within the main mod "[NL] Facial Animation - WIP" folder. The file path for that should be as follows:

steamapps\workshop\content\294100\1635901197\1.5\Defs\FaceTypeDefs\Human

from there open the file with Notepad++ or any similar program and look for any and all instances of <shader>Map/CutoutSkin</shader> and replace them with
<shader>Map/Transparent</shader>

remember to save and that should be good to go. It should be noted that it might also be a good idea to copy and edit that file into your own mod in case of any overwrites from mod updates, but hopefully the issue will be fixed officially in the future