>>2843865How do you even make it work like that in the first place? Tanlines are typically done via UV morphs, and what you should see instead is a texture sliding across the mesh with grotesque results. (I guess you might have a texture that is surrounded by a monotonous dark color?) To my knowledge, you can't manipulate the contrast of PMX textures if that's what you mean. Anyhow, a material morph that changes the values in the texture block works just fine for adjusting tan depth further.
Technically, you could also use a PALETTE for a texture, but that leaves you with an overcomplicated split mesh if you want to still have complex textures like tanlines and naturally flushed areas. You can also incorporate the default texture within a larger gradually changing texture, but that requires a really big brain to set up, as tanlines can only grow or, alternately, fade from UV map edges.