neutral

Having no personal preference.

“a neutral observer”

Having no hue.

“neutral colors like black or white”

Having only a limited ability to react chemically; chemically inactive.

Having no net electric charge.

Lacking distinguishing quality or characteristics.

“a neutral personality that made no impression whatever”

Not supporting or favoring either side in a war, dispute, or contest.

Possessing no distinctive quality or characteristics.

One who does not side with any party in a war or dispute.