"할머니 팔꿈치가 검은색이에요."
Translation:My grandmother's elbow is black.
You are right, possession is omitted here.
And don't to get confused with 할머니는 팔꿈치가 검은색이에요, which means "my grandmother has a black elbow".
I would also translate that as "My grandmother's elbow is black." "팔꿈치" is the subject in both sentences.
So, basically anything goes in Korean as long as it is understood? Ahhahahahahah!
This doesn't make sense. If 발꿈치 is heel then how is 팔꿈치 an elbow? Shouldn't it be the wrist?
I guess the wrist would be 손꿈치 in that way? For your reference the wrist is 손목 and the ankle is 발목.