Did some more looking and it's really evident that it's the Face 3 markings that really need a touch up. Here's Face 3 (top) vs Face 1 (bottom):
https://i.imgur.com/LxEsEuT.png
The markings for Face 1 are pretty clear no matter the skin tone (though paler skin tones seem to wash out the markings more on all faces), but they're noticeably fainter on Face 3 regardless of skin tone.
One of the Seeker faces also has some of the same problem (I think it's Face 4 but my pictures could have been out of order, sorry)
https://i.imgur.com/PeXRWkx.png
