>>2843865>>2844415There's a way of doing this with a single material and without editing the model itself, but you'll have to make a tanline mask based on the original skin texture. The tan parts would be colored black, while the non-tan parts would be white.
Then you would edit the raymmd skin material (I'm using MARUSU's in pic related) and set ALBEDO_SUB_ENABLE to 4 and use your tanline mask as the ALBEDO_SUB_MAP_FILE.