This bug which bethesda decided never to fix seems to appear at random times during a playthrough and i'm not aware of a modder having ever been able to remedy this poor game design like they have most other things that bethesda didn't feel like fixing themselves.

Just wondering if there's anything these days that helps with this eyesore.

Thanks

Do you mean the grey face bug or something else?

Greyface is a result of a mismatch between the baked head assets for a NPC and what's in the records. This usually comes about from multiple mods altering the same NPC_ form for that character, with a conflict loser's head data being overwritten by the conflict winner (which usually has the original head data).

Seam miscoloration may be caused by a variety of mismatches in the texture set for the skin; normal map mismatches, diffuse map mismatches, specular, or even skintone mismatches can all cause it. The use of Object Space Normal Maps at least removes Tangent Space mismatches along the seam geometry, but mismatches in the hi-poly geometry that the obspace normal map was baked from can still cause seams (such as using a CBBE head normal map with a UNP body normal map).

All in all, the miscoloration you are seeing is in all likelihood caused by a mod, not by something inherent in the game itself.