I don't usually support mesh bodies that have got nothing to do with Ruth2 or Roth2. But I've come across an improvement trick for Athena 6 with BoM that nobody seems to know.
The major problem is that the skin on Athena 6's limbs may look weird under certain viewer settings, much like a lighting bug. Some skin areas look brighter or darker than they should.
A minor problem is that alpha masks don't work on Athena 6 although they technically should with BoM.
The reason is because Athena 6 has a chaotic hodge-podge of alpha settings all over it. Parts are set to alpha masking, more parts are set to alpha blending (it's them which may look weird to you or to others), most have alpha off (this is why alpha masks don't work on Athena 6 out of the box).
The solution:
Step 1: Edit your Athena 6 body. All of it, not just any piece. Select it in your inventory while wearing it.
Step 2: Go to the Texture tab.
Step 3: Set the alpha mode to alpha masking.
Now the different shades of skin colour are gone, but your hands and feet may turn partially white. Don't panic, this is supposed to happen and will be fixed in the next steps.
Step 4: Set the mask cutoff to 128. If it is already 128, set it to 127 and back to 128.
The white should disappear, and your body should look normal again. Or better than what you saw previously.
Step 5: Take the body off and put it back on to save the new settings.
Also, you can now wear alpha masks like you can on the system body which might save you from the hassles that come with the alpha cuts on the HUD, and which you can save with outfits. The only limitation is that the alpha masks still don't work on fingernails and toenails.
Should alpha masks stop wearing, just edit the body and set the mask cutoff to 127 and back to 128.
The same method should work on Adonis 4 if you want to use alpha masks with BoM.
Oh, and before anyone tries this on Ruth2 v4 or Roth2 v2: You don't have to, at least not with the "BoM" bodies and Ruth2 v4 "Business". They've got alpha mode controls on the HUD. The "0.8.2.1" versions, on the other hand, are de-scripted and have no HUD, so they require this trick, too, if alpha masks don't work.