I have to be a bit pedantic here… in the real world outside of diving where there exists some semblance of respect for the constructs of everyday science, there is a place where there is no neutral, positive or negative buoyancy. It is a happy place and I like it there.
Neutral, Negative, Positive. These are outcomes and not states of buoyancy. I know it is a hard habit for divers to break – like referring to the Gas Laws as physics when they belong in the realm of chemistry – but I would suggest at this level you should understand the distinction.
Things float, things sink, things maintain their position in the water column: Which of these outcomes corresponds to our state as a diver, depends on the balance between gravity and buoyancy.
It will help us understand this skill more completely, I believe, if we first understand that balance is the variable while gravity and buoyancy are the constants.
So just to recap, there is no such thing as negative buoyancy; that is like saying a color is whitish black or a cup of coffee is Hot Cold.
Positive buoyancy is redundant term at best. But it could also mean that a buoyant force is optimistic; which is just plain wrong.
Neutral buoyancy assumes some all-powerful entity has suspended the Laws of Physics.