The pair are best friends and have taken comfort in each others' company, purring loudly when they are reunited and reassuring each other, which is why the charity wants to rehome them together.
They bump heads and rub up against one another, especially at tea time.
The twosome, thought to be less than a year old, may look almost identical, but have very different personalities, the charity said.
Cola is a cheeky boy and loves his food, while Ace, the female, cannot get enough tickles.
Although a little shy, they have shown that with time and encouragement their true characters shine through. Ace puts on a show; purring loudly and rolling around with her paws in the air, offering her belly for a tickle, while Cola loves treats and chasing his toy goldfish on a string and has recently been trying out sitting on a lap.
Lynne Pothecary, publicity officer at Bracknell and Wokingham District Cats Protection said: "They are growing in confidence every day.
"Although they will probably always be initially shy with strangers, but with a little patience they will form very rewarding relationships.
"For some reason homes are far less easy to find for black cats than other felines and it's sad to see these lovely black cats left waiting in the wings.
"Black cats make up about 23% of all the cats in Cats Protection's care and each one waits around a week longer to be rehomed than the average cat."
Cola and Ace need to be homed without other dogs or cats and ideally with a family whose children are over 12 years of age.
If you could you offer a special home for this lovely little double act, contact the Cats Protection branch on 0845 371 4212, from Monday to Saturday, between 9am and 5pm or email email@example.com