I don’t think that black holes are really black as they are the only ones who have the capacity to bend light. At the centre of the black hole the laws of physics are totally defied, black holes appear black as space is black in colour.
Black holes really look black.
Things look black because they don't reflect or emit light. A black hole is a region of spacetime which light can enter, but can't leave. Black holes don't reflect or emit light, so they look black.
Black holes are not the only things that bend light. Every object with mass bends light. Black holes bend light more than other objects because there is so much mass in such a small region.
Black holes don't have a surface, so they aren't black for the same reason that soot is black. They are black because they don't reflect or emit light. Space also appears black because empty space does not refect or emit light.
"At the centre" is a difficult idea for black holes, because space and time are bent so much near the black hole that the centre becomes a "when" not a "where". The laws of physics aren't defied, but we don't know what the laws are at the time in the centre of a black hole.
(Hawking radiation is predicted to be emitted by black holes. This makes black holes emit light, but for a large black hole Hawking radiation is very low energy and very dim. It is theoretical, it has never been detected, but the theory is very strong and well supported)
(Around the outside of the black hole matter may be falling in. This matter gets very very hot, and so shines very brightly. This means we can see where a black hole is, because we can see the matter that is falling into the black hole)