Hi, I seem to encounter a problem whereas whenever I try to create a sim with the genetics option, I can't change the eye colors/my cc eyes are somewhat disabled or something and I'm wondering if anyone has had this problem?

I believe I've had this problem before, and it had something to do with using outdated or broken CC as your default eye replacements. The issue arises when the CC is marked as "not allowed for random" or it hasn't been updated to include all ages/genders (most commonly infants, since they were a new addition). You can try finding the updated version or a different eye default replacement, or update the CC yourself with Sims 4 Studio, either through a batch fix or by modifying said CC individually. If the problem is isolated to infants, I think the simplest fix would be doing the batch fix, which will be under Content Management > CAS >Update Colors for Infants (Infants Patch).

If the issue is not restricted to only infants, and you can't find the updated version online, you'll want to open up the file by clicking "My Projects," select your Mods folder as your directory, find the eye default replacement CC, and once that's open, go to "Categories" (under the Studio tab), and check that all age & gender flags are checked and that "Allow for Random" (which is at the very bottom under "Part Flags") is checked as well and click "Save" at the bottom right-hand corner. Hope this helps!