As many others have said, black cats just don't stand out and the same goes for black dogs in shelters.
I've always had black cats, when I was young I had a solid black Persian. When I was in high school I adopted a solid black DSH from a shelter. DH and I adopted a solid black kitten, Gus, after our tabby passed away. Gus was from a litter of 9 kittens - 8 solid black, 1 tabby. We didn't intend on taking a kitten home with us that day, but while we were visiting the shelter the tabby was being adopted. We heard them tell her that the litter was being "removed" that afternoon... So, one feisty little black kitten came home with us, too.
I've always had black cats, when I was young I had a solid black Persian. When I was in high school I adopted a solid black DSH from a shelter. DH and I adopted a solid black kitten, Gus, after our tabby passed away. Gus was from a litter of 9 kittens - 8 solid black, 1 tabby. We didn't intend on taking a kitten home with us that day, but while we were visiting the shelter the tabby was being adopted. We heard them tell her that the litter was being "removed" that afternoon... So, one feisty little black kitten came home with us, too.