The event was launched by Cats Protection to celebrate the majesty of monochrome moggies and beautiful black cats.
Black cats are also regularly seen during Halloween, so we thought we'd mark the occasion by asking you to send in your snaps.
Here are 15 of our favourites ...
1. Readers' black cats
Penny Butler's six-month old cat Hocus, who was brought home from a rescue centre Photo: Penny Butler
2. Readers' black cats
Penny Shaw's cats Ronnie and Reggie have to be brothers Photo: Penny Shaw
3. Readers' black cats
Nikita Annice Harston says Willow is a little demon, but loves her dearly Photo: Nikita Annice Harston
4. Readers' black cats
Lisi Lou's cat Luna drinking out of the bath, which is the only place she will drink from Photo: Lisi Lou