I thought I would be able to create some tintable mascara using a facemask, but the lashes always stay black.

I figured it might be a problem with the face overlay layering over the makeup, so I tried making a default replacement for the facial overlay itself with a different color in the eyelash region, but it still doesnt change. Changes to the alpha do show up however.

Is there something I am missing? Does the color come from some other texture? Thank you.

it probably does, few creations got their textures overruled by another one.
I am facing the same troubles with both the simbots.

I have also been trying to figure out a way to change the eyelash color. There is a file called amFaceEyelashes_d - maybe editing this will help?

I tried changing the amFaceEyelashes_d file, but didn't see any difference. I wonder if the color problem has something to do with the TXTC files (which I know nothing about--are they even editable?).