Okay, I did some tinkering over the weekend on a project and made a better more permanent solution for fixing TAB's discoloration around the hips with certain textures and certain hdr environment files.
Alot of it comes down to how high the transparency is set and how bright/light the color in the transparency color channel is. If transparency is low and/or the color is dark, you won't see much if any change. However if they set it to like .90 transparency and/or have blinding white in the color channel, you're in for pain.
So here is G8M with Tab and the Erik materials set applied. It's pretty darn bad and noticeable.
Here's how it looks with the fix implemented and some tiny simple changes to the transparency level and the color in the diffuse/transparency channel. Much more acceptable
The trick I did was to redo what was the hip surface and what was the skin surface. This is pretty easy to do. I've posted to my gallery a guide map you can download
Blank out the textures on a fresh TAB and then load this image into all the diffuse channels. Now set the view in the pane to "wired textured shaded" so you can see both the map and the geometry.
Now with TAB selected, goto into Geometry editor via the Tools Settings pane. Turn on "Use symmetry" and then click the eye icon next to both the "skin" and "glans" surfaces to hide them. You only want the "Hip Skin" Surface visible. Now, highlight all the polys that are in the white part of the texture map. When they're all selected, go back into the geometry editor and click on the "Skin" surface and then right click and choose "Assign Selected Faces to Group". This will make those polys now part of the skin surface. Click on the eye icon next to "skin" and "glans" to make them both visible again.
To make this permanent, you can either save the tab as a scene subset, or you can save it out as a new prop asset.
You will with some textures need to make some small subtle changes to the transparency level in the hip_skin surface. Especially if the setting is something ludicrous like 75 or 90 (Erik here is 75). I would bring it down .05 to .10 lower than what it is. If it still looks too off, in both the diffuse and transparency color channel, add a bit more color if it's super white, or darken it a bit.
That's really it. While it's not 100%, it does make a better fix.