I haven't seen a fix for this anywhere, so my apologies if it already exists. This hack fixes the age group and gender fields for the alien eye Texture Overlay XML file, creating a new default for that file. It does not conflict with alien default eye textures because the texture overlay XML (XTOL) shouldn't be included in any defaults. If you aren't aware of the issue, here's a demo:
Maxis alien skin tone with custom alien eyes:
The same as above, with my fix included:
It should be fine, but if anyone here has a few aliens in play I would appreciate help in verifying that it works.
EDIT: Oops, forgot to attach it. Fixed!
EDIT 2: I'm updating this because I learned that the same problem can occur with alien hybrids: by default, Maxis made the eyes dependent upon the skintone, so a child who inherits alien eyes but not the skintone will end up with textureless eyes. Not cool! The problem is fixed with the same file.
EDIT 3: I asked Pescado to include this in
vampwerefixes. If you have NL, Pets, or Seasons, go use that instead.