Newbie here, with another approach that I stumbled into.

  In Poser 8, you can go into the materials room and pull up your basic windows, then select "browse" and find the texture file for the character you're placing the lekku on. It sounds crazy, but it actually works, and the shading on the character texture map actually creates the subtle skin tone changes which are like the markings on twilek lekku in the movies and comic books. Just don't use the facial texture map...that looks wrong on so many levels. I've used torso, arm, and leg texture maps and gotten a variety of subtle patterns.

  Then go into the advanced materials room and change the color palette on the skin tone. save the color in "customer colors" and apply it to all parts of the character.

  It actually turns out really well, and the extremities for the arms and legs aren't descernable because the attach to the smaller end of the lekku.

  I used this technique on my image "Ta'tyana TEST IMAGE" (see above). The skin texture and character are Lilah for V4. All I did was apply the skin texture from the torso texture file and change the color in the material room. No post work at all.