The hard part is finding any BA2 archives that have any errant 1024 textures that DO NOT have a loose file version of it. This CAN solve all your brown face issues with a little time and patience no matter what mods you use. Sort by file size and boom, theres your missed texture laughing in your face. 2048 textures will have a file size of around 5.4 mb all the 1024 textures will be around 1.3.

To easily spot your missed textures look at its file size in an explorer window.

again, one missed 1024 texture file ruins your day.

If you are using the RealHD 2k face textures.

(I have not tested this, but as i understand it, thats what cathedral does.

Unique NPCs by itself is ALL 1024x1024 face and head textures, so either look for the 2k HD ba2s or extract all the textures and you could probably use Cathedral to upscale them all to 2048x2048.

You guessed it, brown face! You have to find this texture and scale it up to 2048x2048.

If you are using the LMCC HD patch - There is a mistaken 1024x1024 texture in one of the brows or spots textures (cant remember which) which will cause, wait for it.

To those who run into this same issue still.

Fallout 4 brown face fix mod