One cat can be called Coal Ball and the other one can be called Snowball, which is quite symmetrical. Of course, the cat’s name can be chosen according to the cat’s characteristics. For example, if your cat has snow-white hair, you can call it “Snowflake” ” or a name like “Snow White”. If your cat has shiny black fur, a name like "Black Panther," "Dark Night," or "Ball" might be more appropriate.

In short, naming a cat is a fun and loving thing. You can name your cat based on its appearance, personality, or the special relationship between you, so that the name becomes a special bond between you. Remember, no matter what name you choose, the most important thing is to express your love and care for your cat.