In the Dynamic Appearance Texture editor, the controls are listed twice.
It appears they really are duplicates. Colors changed in one place display the new color in the other listing.

I haven't checked everywhere yet, but it occurs for both EYES and TEETH, and HAIR, it doesn't matter if you "keep" or "clear" unused channels.

The textures don't appear to be duplicated on the character's dress, though.

STEPS:
1) "Modify" a character
2) Select the EYE
3) Activate Appearance Editor
4) Notice the duplication, as highlighted in the attached picture

MORE STEPS:
5) Expand the FIRST "Pupil" listing
6) Change the Pupil color in an obvious way, such as from black to white or red
7) Expand the SECOND "Pupil" listing
8) Notice it also displays the new color

DESIRED RESULT:
Each texture should only be listed once.