How do I add individual ringtones to my contacts on my LG G4?

I have the ringtone ID turned on, but when I go to contacts and pick the individual and choose edit the ringtone area is still grayed out. Any suggestions on something else I might need to do?

Since editing the contact and changing the ringtone is the only place you can do that, and LG has chosen to prevent you from doing that, there's not much you can do. (The only way you might be able to change the default incoming ringtone is to freeze or disable Contacts after you put another Contacts app [like Go] into the phone.)