Answer:
Said to have fifty shades
What can touch someone once and last them a lifetime?
A sphere has three, a circle has two, and a point has zero. What is it?
I can be as thin as a picture frame but my insides have many things you can see.
Deep, deep, do they go. Spreading out as they go. Never needing any air. They are sometimes as fine as hair
Though not a plant, has leaves. Though not a beast, has spine. Though many wouldn't need this thing, It's more valuable than wine.