You can easily google Wood Elf and High Elf, and get very different results. Or Deep Gnome and Forest Gnome. But what if you try to look for Protector Aasimar or Scourge Aasimar? How are they different?
Try looking for aasimar of different classes. Necromancer aasimars probably look different than barbarian or paladin aasimars. Or evil aasimars versus good assimars. Or half-celestials and such. That can open up different looks to help you get the different flavors you're looking for.