Black
The exact opposite of white.

It is caused by the absorption of all incident light.

Some things look darker than others because they absorb more light.

The only element to ever do that is Nga (Niggatronium), an element consisting of 500 N (neutrons) and 1 Z (proton) making it among the heaviest element of all time besides U (uranium) which has 92 protons and 92 electrons and is radioactive.

Our pigmentation contains Nga and some people have it more than others.

Though black holes look black as they pull light with their extreme gravity.
Person 1: White isn’t a color.
Person 2: Neither is black.
Person 1: Well white looks bright because it reflects all light.
Person 2: And black looks dark because it absorbs all light.