The black colour helps the cat to hunt at night. But many times through the history black cats were considered to be symbols of evil.
These superstitions exist even today. It is interesting that in American animal shelters people rarely adopt black cats.
In ancient Egypt the cat was loved and admired and when the family cat died it was mummified. The Romans saw the cat in the same way and they were the ones who brought it to Europe. At that time they were seen as a sign of good luck especially if a black one crossed your path.
In the Middle Ages, the church associated them with witchcraft and from then they are seen as symbols of evil.
Instead of being something that was worshiped, black cats became something that was feared. They suffered most in countries where there were witch hunts.
At that time not many countries considered the black cat to be a good sign. In Scotland a black cat on your porch was the sign of prosperity. Fisherman’s women kept black cats because they believed that it will stop anything bad happening to their husband at the sea. Even today the superstition of a black cat crossing your path brings bad luck still lives in Romania and Czech Republic.
In America’s beginnings, black cats were considered to be friends of witches.
There were witch trials where owning a black cat was seen as evidence of Satanic association. Some of those cats were even burned alive with their owners during these trials.
It depends from country to country what people will tell you about black cats. Somewhere they are seen as evil and somewhere they are just like any other cat.